Ebara Solar's Power Module Manufacturing: a Demanding Application for High-Quality Ultrapure Water |
A leading maker of solar power modules, Ebara Solar, Inc. operates an ultrapure water (UPW) production and distribution system to keep manufacturing processes in its new Pennsylvania plant working at peak effectiveness.
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Mike Rosinski
Manager of Facilities Operations |
According to Mike Rosinski, manager of facilities operations, Ebara features dendritic web technology at its Pittsburgh-area manufacturing facility. "Dendritic web modules are lighter, more powerful, and more reliable than photovoltaic alternatives," Rosinski says. "They also score well on benefits like portability, simplicity, safety, stability and environmental impact. We can produce the modules as bifacial units, and their flexibility makes it possible to install them almost anywhere there's sunshine."
The process that produces Ebara Solar's power modules has important features in common with those in the semiconductor industry. Like a computer chip, the solar module is made from high-purity silicon. And the process likewise demands a plentiful supply of ultrapure water.
 Without a reliable flow of UPW, it's impossible to produce the high-quality semiconductor-grade materials that go into Ebara's modules. Non-conductive, contaminant-free water is absolutely necessary to avoid finished-product defects. Ebara's water must be purified to Electronic Grade Quality E-2 specifications, as defined in ASTM D5127-99 (minimum resistivity of 17.5 megohms at 25°C and on-line TOC no greater than 50 parts per billion [ppb]).
"We need a sophisticated, high-volume system to prepare the water for the manufacturing cycle," says Rosinski. "But purifying the water is not the only requirement in keeping a constant supply for our manufacturing process. We also have to maintain the quality as the water passes through the system."
The purified water is used in multiple manufacturing processes. A varied list of applications such as parts rinsing, oxide removal, wet bench rinsing, lithography, polishing, acid mixing and temperature cycling processes all depend on the ultrapure water supply. Plant-wide requirements bring the volume demand to a minimum of 2000 gallons of E-2 grade water per day. |
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