Spire Corporation is addressing the Photovoltaic Manufacturing R&D project goals of improving photovoltaic (PV) manufacturing processes and products while reducing costs and providing a technology foundation that supports significant manufacturing scale-up. To accomplish this, we are focusing our efforts on the design of a large-area utility-scale module and the development of the necessary manufacturing techniques and equipment to manufacture such a module in a high-volume production environment. A three-phase program is under way for developing and demonstrating new automated systems for fabricating very large PV modules ideal for use in multi-megawatt grid-connected applications. We designed a large-area (1.57 m x 3.68 m) 800-W module, and we are developing associated module production equipment that will minimize the total installed system cost for utility-scale PV arrays. Activities in Phase 2 focused on the development of automation for module materials lay-up, cell string busing, and module lamination; enhancements to the cell stringing and lamination processes; and performance testing of large-area modules.

New automated processes and equipment are being developed at Spire Corporation for photovoltaic module, production, under the National Renewable Energy Laboratory's Photovoltaic Manufacturing Technology (PVMaT) project. These processes apply to both crystalline and thin film modules, and address the assembly and testing steps after solar cell lamination. Currently, most module manufacturers use little or no automation for these tasks. The implementation of automated systems is expected to result in labor cost savings, improved product quality, and increased throughput. A reduction in repetitive stress injuries may also be achieved by eliminating product lifting and manual edge trimming tasks. The system designs and automated processes developed in this program are presented.

This report describes the automated systems developed for PV module assembly and testing processes after lamination. These processes are applicable to a broad range of module types, including those made with wafer-based and thin-film solar cells. Survey data and input from module manufacturers gathered during site visits were used to define system capabilities and process specifications. Spire completed mechanical, electrical, and software engineering for four automation systems: a module edge trimming system, the SPI-TRIM 350; an edge sealing and framing system, the SPI-FRAMER 350; an integrated module testing system, the SPI-MODULE QA 350; and a module buffer storage system, the SPI-BUFFER 350. A fifth system for junction-box installation, the SPI-BOXER 350, was nearly completed during the program. A new-size solar simulator, the SPI-SUN SIMULATOR 350i, was designed as part of the SPI-MODULE QA 350. This simulator occupies minimal production floor space, and its test area is large enough to handle most production modules. The automated systems developed in this program are designed for integration to create automated production lines.

Automated processes are being developed at Spire Corporation for photovoltaic (PV) module production. These processes address the module assembly and testing tasks done after lamination. Two automated systems have been designed, built and tested: a buffer system for dispensing and storing modules, and a system for testing module safety and performance. Two additional systems are now under development: an edge trimmer for removing excess encapsulant and back cover film from module edges after lamination, and an edge sealer and framer for dispensing edge sealant and installing frames on trimmed modules. The system designs and automated processes developed in this program are presented.

Spire is addressing the PVMaT project goals of photovoltaic (PV) module cost reduction and improved module manufacturing process technology. New cost-effective automation processes are being developed for post-lamination PV module assembly, where post-lamination is defined as the processes after the solar cells are encapsulated. These processes apply to both crystalline and thin-film solar cell modules. Four main process areas are being addressed: (1) Module buffer storage and handling between steps; (2) Module edge trimming, edge sealing, and framing; (3) Junction-box installation; and (4) Testing for module performance, electrical isolation, and ground-path continuity.

The objective of this work is to reduce the cost and improve the quality of terrestrial photovoltaic (PV) modules by developing automated high-throughput (5 MW/yr) processes for interconnecting crystalline silicon solar cells. A new automated processing system was developed for high-throughput, high-yield solar cell interconnection. The results of extensive processing evaluations with a range of different commercially produced cells are reported. Process yields typically exceeded 98%. No degradation in cell performance was observed. Modules made from cell strings fabricated with the new assembly system were subjected to accelerated environmental testing per IEC 1215 and IEEE 1262 standards. Testing consisted of thermal cycling, thermal and humidity-freeze cycling, and damp heat soaking. All modules passed these qualification tests, with an average power loss of only 2.3%.

This is the Final Technical Report for a program entitled ''Automated Solar Cell Assembly Teamed Process Research,'' funded by the US Department of Energy. This program was part of Phase 3A of the Photovoltaic Manufacturing Technology (PVMaT) project, which addressed the generic needs of the photovoltaic (PV) industry for improved quality, accelerated production scale-up, and substantially reduced manufacturing cost. Crystalline silicon solar cells (Czochralski monocrystalline, cast polycrystalline, and ribbon polycrystalline) are used in the great majority of PV modules produced in the US, accounting for 95% of all shipments in 1994. Spire's goal in this program was to reduce the cost of these modules by developing high throughput (5 MW per year) automated processes for interconnecting solar cells made from standard and thin silicon wafers. Spire achieved this goal by developing a completely new automated processing system, designated the SPI-ASSEMBLER{trademark} 5000, which is now offered as a commercial product to the PV industry. A discussion of the project and of the Assembler is provided.

This report describes work done under the Photovoltaic Manufacturing Technology (PVMaT) project, Phase 3A, which addresses problems that are generic to the photovoltaic (PV) industry. Spire`s objective during Phase 3A was to use its light soldering technology and experience to design and fabricate solar cell tabbing and interconnecting equipment to develop new, high-yield, high-throughput, fully automated processes for tabbing and interconnecting thin cells. Areas that were addressed include processing rates, process control, yield, throughput, material utilization efficiency, and increased use of automation. Spire teamed with Solec International, a PV module manufacturer, and the University of Massachusetts at Lowell`s Center for Productivity Enhancement (CPE), automation specialists, who are lower-tier subcontractors. A number of other PV manufacturers, including Siemens Solar, Mobil Solar, Solar Web, and Texas instruments, agreed to evaluate the processes developed under this program.

The objective of this work is to reduce the cost and improve the quality of terrestrial photovoltaic modules by developing automated high-throughput (5 MW/yr) processes for interconnecting thin silicon solar cells. New low-stress, high-throughput processes have been developed for cell loading, alignment, and inspection, interconnect ribbon handling, flux application, ribbon-to-cell soldering, cell string handling, and I-V testing of assembled cell strings. Both standard thickness (350 μm) and thin (200 μm) cells have been used to evaluate and refine these processes

This report describes work done under Phase 3A of the PVMaT project to address problems that are generic to the photovoltaics (PV) industry. Crystalline silicon solar cells were used in the majority of all terrestrial power modules shipped in 1992. Spire`s analysis in Phase 1 of the PVMaT project indicated that the use of thin ({le}200-{mu}m) silicon cells can substantially reduce module manufacturing costs, provided that processing yields remain as high as they are now for processing standard thickness cells. Because present solar cell tabbing and interconnecting processes have unacceptably high yield losses with such thin cells, the objective of this Phase 3A subcontract is to use Spire`s light soldering technology and experience in designing and fabricating solar cell tabbing and interconnecting equipment to develop high yield throughput, fully automated processes for tabbing and interconnecting thin cells.

Advanced automation processes are being development to reduce the cost and improve the quality of photovoltaic modules. Targeted processes are (1) solar cell assembly, in which the cells are electrically interconnected, (2) module lamination, which encapsulates the interconnected cells for protection from the weather, and (3) module testing, in which a current‐voltage curve is measured under simulated sunlight to quantify module performance. The current status and future plans for this development work are presented.

Automation of photovoltaic production is a necessary element to reduce the cost of PV modules. An important component of the production process is the encapsulation of the cells into an environmentally stable laminate. This process is presently labor intensive, and can be a bottleneck in production. The authors address the issues of automation in loading and unloading the laminate. An economic analysis is presented to justify the automation expense, by considering both reductions in labor and increases in throughput, especially when the process utilizes new “fast-cure” encapsulation materials