TECHNOLOGY IN ACTION ADVERTORIAL Highly coveted in the solar industry: wafer-thin silicon discs Fraunhofer CSP in Saxony-Anhalt develops solutions for efficient, cost-effective and reliable solar modules enter 814
industry. Under this premise the Fraunhofer Center for Silicon Photovoltaic CSP in Halle carries out applied research throughout the entire process chain for the production of wafer-based silicon solar modules. CSP is taking part in the “Intersolar Europe” trade fair for the solar industry in Munich for the fourth time. This year it has even been nominated for an Innovation Award. “No, the diamond wire does not sparkle,” sais Stephan Schönfelder, holding it up to the light. The wire looks grey compared to the shiny reddish gold steel wire with brass coating. The diamond coating feels rough and produces a faster dissipation of
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merging from the crisis stronger – this phenomenon should also apply to the solar
silicon blocks in the coveted thin wafers. Time is money – with the production of these grey discs that are used as the base plate for solar cells too. Wafer-based silicon solar cells have an 80 percent share of the global production of solar cells and modules. “Roughly a third of the costs for a silicon solar module is accrued before production of the wafer even starts,” says Stephan Schönfelder and he adds that the research is about reducing these costs, even more so due to the crisis on the photovoltaics market. Schönfelder coordinates the research project which the diamond wire saw is involved even in the name: “DiaCell – innovative wafering technologies from the substrate to the photovoltaics module”. The mechanical engineer wrote his doctoral thesis at the Fraunhofer Institute for Mechanics of Materials IWM in Halle. Its theme is based in the field of the mechanics of thin silicon substrates. He is therefore an expert when it comes to the mechanical properties of thin silicon wafers and in producing them in high quality but as cheaply as possible.
Schönfelder holds a disc between his two index
fingers. It is roughly 180 micrometres thin, which is the standard, he says, adding that this research project is about producing even thinner silicon wafers, among other things. At the same time they are looking at reducing the breakage rate too. Partners in the project come from regional industry: SILTECTRA from Dresden, bubbles & beyond from Leipzig and Innotech Solar from Halle. An industry compatible pilot line has been set up
at Fraunhofer CSP where the wafers run through the entire production process chain. Existing and new production technologies are tested and
optimised here over and over again. As research cannot just rest at having a fantastic idea that changes the intermediate product in the desired way, you also have to look at what influence this idea has on the successive elements in the value chain, says Schönfelder. DiaCell has the job of developing technologies that reduce costs for the entire value chain. As a result, mechanical experiments showed that the diamond wire sawn wafers also have one disadvantage: they break easily in the sawing direction. Furthermore, the diamond wire saw causes chips: very fine powder that contaminates the wafer disc and entails several complex chemical steps in the cleaning process. To save time and money here too, bubbles & beyond is developing so-called “intelligent fluids”
together with Fraunhofer CSP. The
development of fluids goes hand in hand with the process development and may cut out whole sections in the entire production process in the end.
CSP is researching splitting the wafer without any material loss with the project partner SILTECTRA. After all, every sawing gap causes material loss in the ballpark of one wafer thickness. That is a great deal in relation to the approx. 180 micrometre thin standard disc and may mean up to 50 percent material loss. These kinds of modules are exposed to extreme wear - continue reading here.
Highly Coveted Email:
anja.ruedinger@img-sachsen-anhalt
www.invest-in-saxony-anhalt.com
Development consortium targets smarter surface coating
smarter approach to applying advanced thin-film coatings to high value engineering products is being developed by Teer Coatings, Cobham Technical Services and The Open University. The collaborative project, which is co-funded by a £577,000 award from Innovate UK - the UK's Innovation Agency - will develop a groundbreaking practical tool for simulating sputter coating, to deliver a right-first-time process. The development project brings together experts on non-equilibrium plasma physics, computer-aided engineering software for modelling and simulating electromagnetic and related physics effects, and the design and use of the physical vapour deposition (PVD) magnetron sputtering tools to apply coatings that are important in a wide range of high value manufacturing applications. The key aim is to develop a practical software-guided approach to thin-film coating that is both accurate and fast. This tool will provide an intelligent and automated analysis of a proposed deposition process that will help users optimise the performance of a coating tool and the characteristics of a surface coating applied to workpieces.
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software. These will provide the means for users to model the entire process, from the plasma field, via ion bombardment of the 'target' coating material, to subsequent deposition. The software will also take into account the properties of the vacuum processing chamber,
including the magnetic fields and Such an approach will potentially
eliminate the need for prototyping and trials, and will be relevant to intelligent and optimised surface coatings, enabling performance advances in a wide range of engineering sectors. The collaborative development project will run until September 2016. A team from The Open University will advise on the physics of the magnetically-confined plasmas that are generated in magnetron tools to vapourise coating materials for deposition onto the workpieces, and provide accurate feedback on the actual performance of the new software-guided process. Cobham Technical Services - developer of the Opera finite-element analysis simulation tool-chain for modelling, simulating, analyzing and auto-optimising electromagnetic effects - will develop application-specific solvers for its
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substrate movement. The project is led by Teer Coatings, part of the Miba Coating Group. As this company manufactures thin-film deposition tools and provides specialist coating services, it is ideally placed to evaluate the new software-guided approach by using it in conjunction with its magnetron tools, and validating its efficiency on a very broad variety of workpieces - from metal cutting tools to medical implants. The software-guided approach also offers the opportunity to dramatically reduce the costs associated with sputtering target materials. It is common for less than half of each sputtering target to be depleted before replacement, because of uneven wear. Increasing target utilisation by just a few percent has the potential to save the coating industry hundreds of millions of dollars annually in material costs. Many advanced engineering components such as bearings, turbine blades,
valve parts and electronic
circuits are given special surface treatments to improve performance, in terms of characteristics such as resistance to wear,
lubrication, biocompatibility and
electronic properties. These surface coatings are often extremely thin, and can be less than 1/100th of the diameter of a human hair, but often need to survive and function in harsh environments, such as in a turbo- charger or at the tip of a cutting tool.
For more information please contact Amanda Machado at:
Cobham Technical Services +44 (0)1865 370151
vectorfields.info@
cobham.com
www.OperaFEA.com enter 815
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