Circuits Assembly - October 2008 - (Page 40)

Alternative Energies Photovoltaics in EMS Sector Have spare capacity? Simply bolt-on solar cells! T Darren Brown is alternative energy development manager at DEK (dek.com); dwbrown@dek.com. This column will run periodically in 2009. he solar cell sector is buoyant, booming even. What’s interesting for those like me with experience in other process-driven sectors – in my case surface mount pre-placement technology – is the number of parallels and similarities in business models deployed and the choices to be made. My company has been looking at the potential of the solar cell manufacturing sector for some time. In fact, we have a division based in Japan that continued to develop the thick film technology once the mainstay of our commercial offerings Equally useful is the expertise required to develop a metallization solution for solar cell manufacture fits handin-glove with core competencies we have in screen printing. So, as a capital equipment vendor, it could be said we have been able to “bolt on” a new dimension to our business simply by leveraging existing skills and resources to deliver solutions into a new sector and take it mainstream. It wasn’t quite that simple, of course, but I’m sure you get the point. That point, however, is not so much about equipment vendors, but about the parallel I see among a segment of our traditional customer base: screen printer end-users who are EMS firms. They, too, have skills and resources at their disposal, and many now have the spare capacity to pursue other revenue streams. It’s clear to me EMS providers are similarly recognizing the potential of the solar cell sector. In the world of silicon solar cells, metallization is a vital part of the photovoltaic manufacturing process that effectively attaches electrical interconnect structures to the silicon substrate. Other parts of the solar cell manufacturing process include taking the cells, making them into panels, and packaging them as final products ready for installation – facing the sun! Preceding the manufacturing process is the provision of complex front-end chemistry to create the silicon or glass substrates – the raw material for a photovoltaic cell. The silicon tile, either a monocrystalline or multicrystalline type, features a photosensitive coating that generates an electrical potential when exposed to light. During metallization, physical connectivity is secured to the substrate surfaces to make use of this current. Precision screen printing is the process of choice used to image a fine lattice of conductive ink connections on the solar-facing surface, which gives something to connect to electrically. The lattice pattern needs to be fine so the metallization covers the bare minimum of the substrate’s surface area, leaving the maximum area exposed to light, therefore generating electric current. The parallels with ultra-fine-pitch surface mount printing are obvious. Profiled oven technologies are also deployed to cure the inks and fire the silicon substrates – another recognizable SMT parallel. However, perhaps the most significant parallel comes Circuits Assembly OCTOBER 2008 when looking to implement a photovoltaic production facility. Do you go for an “out-of-the-box” solution where your chosen “integrator” vendor supplies everything – every piece of process equipment and sometimes even the factory building itself? Or do you spec each piece of equipment separately to achieve a best-in-class solution? Does this sound familiar? It’s a dilemma faced by most SMT assemblers: Go for a whole line solution from a single vendor, or spec printers, chipshooters, flexible mounters and ovens separately. Then there’s another parallel – or is it a convergence? – between SMT and photovoltaic assembly. And it takes us back to EMS providers. They tend to have a business model that calls for diversification in the provision of services related to their manufacturing capability, and a propensity to capitalize on new processes and new deliverables, especially in an identifiably buoyant market. With many EMS firms experiencing a downturn in their established electronics business, they see spare capacity in manpower and factory real estate and seek new revenue streams. That’s where solar cells fit. I am seeing EMS companies using their resources to get into the photovoltaic market. They, too, can simply bolt on a new service and revenue stream. As it happens, they can’t repurpose existing SMT electronics assembly equipment for the metallization process, but they can deploy Lean manufacturing principles and astute commercial expertise. It’s simply a question of investing in the plant necessary to begin production. Anyone familiar with a typical EMS business model will know capital equipment expenditure usually represents a surprisingly small percentage of the overall project cost. Therefore, new machines tend to be easy to justify against the order book. Of course, they still face the big decision: whether to outsource the whole thing to an integrator (though they probably already have the factory space) or tool up for a best-in-class process solution. Then again, that’s not to say necessarily the two are mutually exclusive; it depends what products your integrator vendor supplies within its package. But you need to know enough to know the difference. And differentiation is the name of the game for EMS providers, as they strive to add value to what is, for the most part, a highly commoditized service. As with any competitive market, photovoltaic is becoming hotly contested and surely has commoditization written all over it, as demand for greener, renewable sources of energy escalates. Solar cell technology is already highly desirable. But how do you make solar cells more desirable than your competitor’s? I believe the parallels with the SMT sector hold the answer to adding the right kind of value. Some of us have been here before! That means EMS providers entering the sector need to get it right the first time. n circuitsassembly.com 40 http://www.dek.com http://www.circuitsassembly.com

Table of Contents Feed for the Digital Edition of Circuits Assembly - October 2008

Circuits Assembly - September 2008 Contents Letters Caveat Lector Industry News Market Watch Talking Heads Global Sourcing Screen Printing Better Manufacturing 'Checking Up' on Medical Electronics Solder Ball Attachment Using Laser Soldering Improving QFN Reliability Reflow Soldering Tech Tips Test and Inspection Process Doctor Pb-Free Lessons Learned Alternative Energies Eastern Advances Product Spotlight Ad Index Assembly Insider Technical Abstracts

Circuits Assembly - October 2008

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