Category Archives: Energy Storage

The Riley Report


April 14, 2009

Non-traditional Applications of Jet Dispensing
by George A. Riley, Contributing Editor

While jetting of fluids has become common in semiconductor packaging, it is finding new applications in emerging fields. At the recent SMTA Pan Pacific Symposium, Alec Barbiarz of Asymtek described jetting opportunities in medical analytics, high-intensity lighting, active-matrix displays, green energy, and 3D assemblies. In most of these applications, the jetted materials are not just part of the packaging, they are an essential component of the device.

For example, the growing life sciences field of on-chip blood analysis requires depositing chemicals into wells in each die of a semiconductor wafer. Both the amount dispensed and the location must be carefully controlled, while the large number of die per wafer calls for high-speed dispensing. That combination &#151 carefully controlled, high speed &#151 defines the territory of today’s jetting.

The blue LED has lighted the way to high-brightness white illumination, but to produce white light, the blue must first be covered by a yellow filter. The color temperature of the resulting white light is critically dependent upon the composition, thickness, and the yellow phosphor layer’s uniformity of distribution. Slurry-dispensing leaves a thicker coating of phosphor granules at the LED’s center, thinning towards the edges as the granules settle. Jetting gives a uniform, repeatable layer.

A future replacement for our ubiquitous liquid-crystal flat panel displays may be active-matrix organic light-emitting diodes (AMOLED). A fluid sealant must be dispensed around each display element before glass lamination, so the largest current AMEOLED display requires nearly 900 individually-dispensed seals.

The higher speed of jet dispensing substantially lowers seal dispensing costs by replacing multi-head needle dispensers with a single jet dispenser. An even greater time and cost saving results from jetting filler material inside the seals. The piezoelectric jet dispenses multiple small drops uniformly spaced inside the seal boundary before lamination, saving hours compared with needle-dispensed fluid penetrating along an edge.

Green energy applications of fluid dispensing include both photovoltaics and fuel cells. Photovoltaics require fluid dispensing from beginning to end. The wafers must be uniformly sprayed with a dopant before entering the drive-in furnace. The backside coating of the wafers is also printed or sprayed.

Electrically conductive “buss bars” may be jet dispensed across the wafer to join the cell conductor traces and form a panel. This application is similar to the replacement of bond wires with jetted conductive adhesive edge connections on 3D parallel or offset chip stacks, as shown in my October, 2008 Advanced Packaging article “How 3D is Stacking Up.”

Direct methanol fuel cells (DMFC) are a challenging emerging application for jetting, since they must handle both volatile and corrosive fluids. Holes etched in a silicon wafer permit water and methanol (the fuel) to reach an anode-side catalyst layer where they are reduced, allowing protons to pass through a permeable proton exchange membrane to the cathode side. A counter-current of electrons flows externally from anode to cathode, completing the electrical circuit.

The proton exchange membrane is a DuPont perfluorosulfonic acid polymer, which can be jet-dispensed with a volatile solvent. The catalyst layer may be carbon black, dispensed as an ink. Complications include that the carbon black can settle and clog a jet, the ink may not properly wet the surface, and the carbon forms a brittle layer when it dries. The polymer solvent may evaporate, sealing the jet nozzle, and the wetted portions of the jet must resist attack by sulfonic acid.

The automated dispenser includes a mass flow calibration function. When operated in a dam-and-fill mode it has produced uniform dry film thicknesses of 40µm +/- 5.

In summary, the enhanced capabilities of fluid jetting are opening up new, non-traditional electronic and semiconductor assembly applications.

Contact George Riley

Debra Vogler, senior technical editor, Photovoltaics World

March 23, 2009 – Intermolecular, Inc. recently announced that a former solar exec from Applied Materials, Craig Hunter, has joined the company as VP and GM of its solar business group. Hunter founded and managed Applied’s thin-film solar business and was instrumental in formulating the strategy for the company’s SunFab thin-film line.

A major task for the new exec is to leverage Intermolecular’s High-Productivity Combinatorial (HPC) technology, which has already been used to gain R&D efficiencies in the semiconductor industry, and apply it to solar PV research.

The solar energy sector represents a strategic growth opportunity for Intermolecular — the company cites a Crosslink Capital projection of a 53% CAGR from 2008-2012 in the solar sector, shared at the 2009 SEMI Industry Strategy Symposium (ISS). New materials innovation and discovery are key drivers for advancements in energy conversion efficiency and cost reduction for solar panels.

“The HPC platform is a disruptive technology for boosting R&D in semiconductor applications,” Intermolecular’s CEO, David Lazovsky, told PV World. “We’re designing risk out of the process [of materials R&D].” The company is confident about the ability of its technology to transfer directly over to solar applications. “The manufacturing technologies currently in production for PV applications are the same used in the semiconductor industry,” he said. “The lines between semiconductor process technology and solar technology have not just blurred, they’ve disappeared.”

The solar industry now faces a situation where supply is outpacing demand, which is putting a lot of pressure on manufacturers. “Suddenly, a rising tide is not lifting all boats,” and companies have to differentiate themselves based on technical capabilities, Hunter said. Intermolecular’s HPC technology, he noted, can accelerate that differentiation as well as the solar roadmap that requires quickly getting solar conversion efficiencies up and manufacturing costs down.

One area that could immediately benefit from applying HPC to solar manufacturing is optimizing surface morphology — i.e., texturing a wafer, to allow light to be bounced and bent to ensure maximum absorption. Other challenges that could potentially benefit include optimizing anti-reflective coatings (to reduce reflection) and minimizing recombination losses that occur in the solar cell itself. The company expects its HPC technology to be applicable to crystalline silicon, thin-film silicon, and other types of solar cells, (e.g., CIGS, CdTe).


Using HPC technology to address the challenge of texturing ZnO:Al films, Intermolecular ran >500 process experiments and complete >8000 characterization sets in just 3 weeks. Shown above are just a few of the AFM images with variability in shape and size of the textured features. (Source: Intermolecular)
Click here to expand

Next on Intermolecular’s PV agenda is identifying areas within the recently passed US stimulus package in which the company can participate, and the company is currently talking with potential partners to leverage stimulus funding, Lazovsky told PV World. A key factor, however, will be how PV industry consortia are defined. Unlike the semiconductor industry which includes consortia such as SEMATECH, IMEC, and Selete, “consortia in the solar sector are not as well-established…for presenting immediate opportunities for direct engagement,” he explained. Booming growth in the solar industry the past five or so years has been a kind of “a rising tide lifts all boats” period, so “there wasn’t the need for consolidation, creation of alliances, etc.,” he noted. “What you’re seeing now in the last several months already, industry structure is starting to be re-examined and people are starting to take a serious look at those issues, but it won’t play out overnight, it will take several years for that to occur.”

The incredible growth also has been spurred by attractive incentives by the German and Spanish governments. “You had a period where supply couldn’t keep up with demand,” Hunter told PV World. “That, coupled with the low barriers to entry for plain vanilla thin-film and crystalline silicon technologies, meant that a lot of people could jump into the industry by buying equipment or turnkey equipment lines, and everybody could sell out whatever they could make.” This situation meant there was no real need to develop the kind of industry discipline such as in the semiconductor industry. “So it’s really the early days…I think you’ll see that development in the coming years.” (There are opportunities, he thinks, to initiate such industry groups now among relevant players — particularly in the US, “where the ROI of stimulus dollars can be maximized, not just for advancements of alternative energy technologies, but also for general economic stimulus and job creation.”) — D.V.

This article was originally published by Photovoltaics World.

Mar. 10, 2009 – With promises of government subsidies and power utilities slated to buy excess power from customers at relatively high prices in fiscal 2010, demand for solar panels is expected to climb in Japan — but domestic solar cell producers are facing intense competition from other sectors and foreign entrants, reports the Nikkei Business Daily.

Sharp Corp., Kyocera Corp., and other major Japanese solar cell manufacturers will likely face more intense competition as domestic chemical companies, as well as Chinese, Taiwanese and other foreign solar cell makers, gear up to enter the market. And a strong yen is making things even tougher for domestic suppliers to fend them off.

Foreign competition

Solar cell manufacturers from around the world showed off their cutting-edge technologies at the recent 2nd International Photovoltaic Power Generation Expo. Taiwan’s Sun Well Solar Corp. plans to start selling its thin-film solar cells in Japan through a major trading firm as early as this year. Its production capacity is slated to rise by 350% to 45,000kW this year.

Chinalight Solar Co., which manufacturers and sells machinery, intends to start selling its solar cells in Japan through its machinery sales network. Many Chinese and Taiwanese solar cell makers have been selling most of their output in Europe, but sales there have been hit by the economic downturn.

Domestic competition

Some Japanese chemical companies are also making forays into the solar cell business, the Nikkei Business Daily notes. Mitsubishi Chemical Corp. is working on an organic thin-film solar cell with a goal of developing building materials with built-in solar cells. Fujikura Ltd. displayed pigment-sensitized solar cells at the Expo.

Meanwhile, major Japanese solar cell makers’ expo exhibitions are focused on products offering higher energy conversion rates. Kyocera displayed a new type of solar module that it plans to begin mass-producing in fiscal 2009. This polysilicon module features a type of cell that maximizes the light-capturing area by placing the electrodes on its back.

Mitsubishi Electric Corp. is promoting a polysilicon solar cell that utilizes infrared rays more efficiently than existing products. Sharp is planning to raise the suggested per-kilowatt retail prices of its mainstay models by about ¥20,000, citing an improvement in efficiency. Sharp’s booth at the expo displayed a solar module that requires an installation space of ~13 sq. m.

Home-use solar power systems

In the Japanese market for home-use solar power systems, numerous low-price overseas makers are establishing their presence, especially in light of new government subsidies.

In January, the Japanese government began accepting applications for subsidies for the installation of household solar power systems; the program will resume in fiscal 2009 after a hiatus. To be eligible, models must be priced at <¥700,000/kW, including installation costs. However, the current typical price of solar devices is around ¥800,000/kW.

Thus, in January, Ecosystem Japan which sells 50,000 solar power systems annually, lowered prices so that all products are priced at no more than ¥700,000/kW. Given that wholesale prices remain unchanged and Sharp’s prices are lowest, selling Sanyo and Kyocera products is now less appealing to the firm.

Sharp’s price advantage over other domestic firms, however, does not guarantee success because of foreign competition. For instance, Ecosystem Japan has been receiving numerous supply proposals from Chinese and Taiwanese manufacturers.

West Holdings Corp., a home improvement firm that sells solar power systems at Yamada Denki Co. outlets, recently switched its main supplier from Sanyo Electric Co. to China’s Suntech Power Holdings Co. to save money. The company is also receiving further offers from other Chinese and European firms.

The strong yen is making it difficult for domestic players to hold off the foreign onslaught. “As competition intensifies, solar cell makers cannot sell at their ideal prices,” said a West Holdings executive. “Sales companies are carefully selecting their suppliers.”

This article was originally published by Photovoltaics World.

by Debra Vogler, senior technical editor, PV World

In addition to discussions about cooperating on clean energy efforts going forward, the daylong US-China Clean Energy Forum (Feb. 13) also showcased how solar technologies tie together in the real world — integrating a parking lot-based solar array, electric vehicles, smart grid technology, energy storage, and high-performance battery recharging systems.

Two of Pacific Gas & Electric’s electric powered vehicles were on site and hooked up to Applied’s solar power plant for recharging during the event along with demonstrations of smart metering technology (see photo below). One of the featured models was a Mitsubishi iMiEV, a pre-production version of the electric vehicle to be released in Japan this summer; PG&E is working with Mitsubishi Motors to do user acceptance testing and real-world drivability testing. The vehicles, which can accept direct DC fast charging as well as 120V AC, are being used to test out the utility’s smart charging program, according to Efrain Ornelas, environmental technical supervisor for clean air transportation at PG&E. Smart charging focuses on charging cars at night to minimize impact on the grid, as the utility has more wind-generated electricity available for use at that time (at least in some territories).


Applied Materials CTO Mark Pinto (right) and Han Wenke, director general of the Energy Research Institute of the National Development and Reform Commission (left), demonstrate an electric vehicle powered by solar energy. Inside the car: (left) Saul Zambrano, director of clean air transportation, and (right) Hal LaFlash, director of emerging clean technology policy, both from Pacific Gas and Electric Co. (Photo courtesy of Applied Materials)

In addition to PG&E, companies featured at the event were conEdison, Gridpoint, Better Place, and AeroVironment. The Better Place business model is one in which consumers subscribe to transportation as a service, similar to a cell phone subscription model. In the Better Place model, the company effectively owns the batteries in electric vehicles, providing consumers with the ability to replace them with fully charged batteries at its network of recharging stations and battery swap stations — this is key to make owning an electric car affordable and convenient. The company has signed agreements to expand its electric car infrastructure in Israel, Denmark, California, Hawaii, Australia, and Canada.

Meanwhile, AeroVironment approaches the problem of “range anxiety” — i.e., people afraid to take electric vehicles on long trips because of the uncertainty of being able to recharge batteries in a timely manner — by offering a fast charging capability based on its PosiCharge technology. According to the company, a range of PosiCharge EV fast charge systems enable EV drivers to have access to a 10 minute battery charge when and where needed. — D.V.

February 4, 2009: Infinite Power Solutions Inc., which develops and commercializes solid-state, rechargeable thin-film batteries, has sent out its first pre-production shipments of its new THINERGY micro-energy cell (MEC), the company announced in a news release.

MicroStrain and Lockheed Martin were among several companies to receive the MECs from IPS’s new manufacturing facility in Littleton, Colo., the release said.

Although often referred to in the industry as a thin-film battery, IPS’s thin-film micro-energy cells actually represent an entirely new class of energy storage device that combines a micro-thin, flexible form factor with unmatched rechargeability, cycle life and power performance, according to the company.

These component class devices enable many years of operation and are designed to last the life of the products they serve, eliminating the need for, and cost of, battery replacement.

“We believe micro-energy cells will help enable a new class of miniature, networked, autonomously powered mobile electronic devices that are perpetually recharged via ambient energy harvesting,” Macy Summers, Lockheed Martin, said in the release.

January 26, 2009: A team of scientists at the US Department of Energy’s (DOE) Brookhaven National Laboratory, in collaboration with researchers from the University of Delaware and Yeshiva University, has developed a new nanotech-based catalyst that could make ethanol-powered fuel cells feasible. The highly efficient catalyst performs two crucial, and previously unreachable steps needed to oxidize ethanol and produce clean energy in fuel cell reactions. Their results are published online in the January 25 edition of Nature Materials.

Like batteries that never die, hydrogen fuel cells convert hydrogen and oxygen into water and, as part of the process, produce electricity. However, efficient production, storage, and transport of hydrogen for fuel cell use is not easily achieved. As an alternative, researchers are studying the incorporation of hydrogen-rich compounds, for example, the use of liquid ethanol in a system called a direct ethanol fuel cell.

“Ethanol is one of the most ideal reactants for fuel cells,” said Brookhaven chemist Radoslav Adzic. “It’s easy to produce, renewable, nontoxic, relatively easy to transport, and it has a high energy density. In addition, with some alterations, we could reuse the infrastructure that’s currently in place to store and distribute gasoline.”

A major hurdle to the commercial use of direct ethanol fuel cells is the molecule’s slow, inefficient oxidation, which breaks the compound into hydrogen ions and electrons that are needed to generate electricity. Specifically, scientists have been unable to find a catalyst capable of breaking the bonds between ethanol’s carbon atoms.

But at Brookhaven, scientists have found a winner. Made of platinum and rhodium atoms on carbon-supported tin dioxide nanoparticles, the research team’s electrocatalyst is capable of breaking carbon bonds at room temperature and efficiently oxidizing ethanol into carbon dioxide as the main reaction product. Other catalysts, by comparison, produce acetalhyde and acetic acid as the main products, which make them unsuitable for power generation.


Model of a ternary electrocatalyst for ethanol oxidation consisting of platinum-rhodium clusters on a surface of tin dioxide. This catalyst can split the carbon-carbon bond and oxidize ethanol to carbon dioxide within fuel cells. (Image courtesy of Brookhaven National Laboratory)

“The ability to split the carbon-carbon bond and generate CO2 at room temperature is a completely new feature of catalysis,” Adzic said. “There are no other catalysts that can achieve this at practical potentials.”

Structural and electronic properties of the electrocatalyst were determined using powerful x-ray absorption techniques at Brookhaven’s National Synchrotron Light Source, combined with data from transmission electron microscopy analyses at Brookhaven’s Center for Functional Nanomaterials. Based on these studies and calculations, the researchers predict that the high activity of their ternary catalyst results from the synergy between all three constituents — platinum, rhodium, and tin dioxide — knowledge that could be applied to other alternative energy applications.

“These findings can open new possibilities of research not only for electrocatlysts and fuel cells but also for many other catalytic processes,” Adzic said.

Next, the researchers will test the new catalyst in a real fuel cell in order to observe its unique characteristics first hand.

This work is supported by the Office of Basic Energy Sciences within DOE’s Office of Science.

January 20, 2009: Scientists have always wanted to take a closer look at biological systems and materials. From the magnifying glass to the electron microscope, they have developed ever-increasingly sophisticated imaging devices.

Now, Niels de Jonge and colleagues at Vanderbilt University and Oak Ridge National Laboratory (ORNL), add a new tool to the biology-watcher’s box. In the online early edition of the Proceedings of the National Academy of Sciences, they describe a technique for imaging whole cells in liquid with a scanning transmission electron microscope (STEM).

“Electron microscopy is the most important tool for imaging objects at the nano-scale — the size of molecules and objects in cells,” said de Jonge, who is an assistant professor of Molecular Biology & Biophysics at Vanderbilt and a staff scientist at ORNL. But electron microscopy requires a high vacuum, which has prevented imaging of samples in liquid, such as biological cells.

The new technique, liquid STEM, uses a microfluidic device with electron transparent windows to enable the imaging of cells in liquid. In the PNAS article, the investigators demonstrate imaging of individual molecules in a cell, with significantly improved resolution (the fineness of detail in the image) and speed compared to existing imaging methods.

“Liquid STEM has the potential to become a versatile tool for imaging cellular processes on the nanometer scale,” de Jonge said. “It will potentially be of great relevance for the development of molecular probes and for the understanding of the interaction of viruses with cells.”

The technique will also become a resource for energy science, as researchers use it to visualize processes that occur at liquid: solid interfaces, for example in lithium ion batteries, fuel cells, or catalytic reactions.

“Our key innovation with respect to other techniques for imaging in liquid is the combination of a large volume that will accommodate whole cells, a resolution of a few nanometers, and fast imaging of a few seconds per image,” de Jonge said.

January 19, 2009: Worldwide nanotechnology thin film lithium-ion batteries are poised to achieve significant growth as units become more able to achieve deliver of power to electric vehicles efficiently, according to a new report by Electronics.ca Publications.

The market research network predicts the market for thin-film lithium-ion batteries will reach $9.1 billion by 2015, from $911 million in 2008.

According to the study, economies of scale leverage the lithium-ion battery nanotechnology advances needed to make lithium-ion batteries competitive. Unlike any other battery technology, the report said, thin-film solid-state batteries show very high cycle life. Using very thin cathodes batteries have been cycled in excess of 45,000 cycles with very limited loss in capacity. After 45,000 cycles, 95% of the original capacity remained.

Then there is the problem of translating the evolving technology into manufacturing process. What this means is that the market will be very dynamic, with the market leaders continuously being challenged by innovators, large and small that develop more cost efficient units. Systems integration and manufacturing capabilities have developed a broad family of high-power lithium-ion batteries and battery systems.

Electric Vehicles depend on design, development, manufacture, and support of advanced, rechargeable lithium-ion batteries. Batteries provide a combination of power, safety and life. Next-generation energy storage solutions are evolving as commercially available batteries. Lithium-ion batteries will play an increasingly important role in facilitating a shift toward cleaner forms of energy.

January 16, 2009: Microfluidics, a subsidiary of Microfluidics International Corp., has filed for a patent on its Microfluidics Reaction Technology (MRT), which will enable companies and research organizations to develop and manufacture smaller-sized nanoparticles than previously possible and to do so more efficiently than with other methods, according to a company news release.

The technology was presented at the Nano Science and Technology Institute (NSTI) Nanotech 2007 and 2008 conferences and won a Nano 50 award in 2007 as one of the most innovative ideas that will revolutionize nanotechnology in the near-term and beyond.

The patent covers processors, processes, and applications that are used to produce nanoparticles at high volume, high purity, and low cost. MRT can also be used for synthesis of fine chemicals through single or multiphase chemical reactions or physical processes such as crystallization. Another key use is process intensification, or combining chemical processes in ways that increase manufacturing efficiency, reduce energy use, and result in purer products.

MRT has a wide range of applications, including production of pharmaceutical nanosuspensions and of nanomaterials that are used for fuel cells and photovoltaics. It is particularly applicable for those pharmaceutical applications where the trend is to go to very small particles that have precise polymorph control. Microfluidics has demonstrated MRT by creating nanosuspensions of a variety of injectable or inhalable drugs, including cancer therapies, antibiotics, antihistamines, and non-steroidal anti-inflammatories, among others.

by Meredith Courtemanche, contributing editor, PV World

Jan. 12, 2009 — With the economy and oil prices plummeting, the solar cell industry is fighting to retain the interest, investment, and production volumes it gained as a result of the recent energy crisis and environmental awareness. Rudolph Technologies Inc. introduced a software package targeting the still-troublesome area of photovoltaic cell efficiency, hoping to bring solar cells closer to grid parity through reduced costs and inefficiencies.

Rudolph pulls product value from a mature production field — semiconductors — for its Discover Solar software package. The company asserts that cell efficiencies still have significant room for improvement, while competitions and attention to costs have escalated. Discover Solar is designed to automate process control and perform root cause analysis closer to real time.

Discover Solar is a fab management software tool designed to help photovoltaic (PV) manufacturers increase cell efficiency and reduce costs. Rudolph claims that the software, which operates with in-line data, reduces scrap and downtime by identifying root-causes of yield issues. For a PV cell manufacturer producing 7,500,001 30-MWp line wafers per year, the Discover Solar tool can cut out $495,000 in scrap, $90,000 in inefficiencies, and $87,600 in engineering costs, according to Rudolph, citing cost analysis data from a PV fab.

While Discover Solar is based on Rudolph’s semiconductor manufacturing process control software, the company acknowledged that they had to consider “everything differently” when designing software for PV lines, primarily due to the high volume of silicon wafers and the varying degrees of raw material quality. Discover Solar incorporates a re-engineered database structure and analysis engine optimized for the requirements of high-volume photovoltaic production. “Not a lot of in-line metrics are available in PV facilities, as compared to the semiconductor world,” states Mike Plisinski, VP and GM of Rudolph’s data analysis and review business unit. Root causes of useless solar cells or those with poor energy conversion efficiency are less easily tracked, he added. Using in-line metrology, equipment, and cell test data, the software’s path analysis equations allow for faster and more automated correlation between a problem and a specific line, line tool, or batch of wafers.


Discover Solar automatically identifies specific tool or process issues. (Source: Rudolph Technologies)

Discover Solar allows engineers to pinpoint a problem on the process tools (e.g., chambers, tubes, zones, or print tables), inline metrology (resistivity, thickness, color), tool input parameters (temperature, pressure, gas flow), and cell test data, by showing out-of-spec results after a particular process during PV manufacturing. The software can also call out a bad batch of wafers by identifying variations between wafers run over the same recipe in the same tools. Finally, it can alert users to “hidden” correlations between scrap or inefficient cells and multiple errors at different steps, resolving or preventing “second-order effects,” Plisinski asserts.

To accommodate the throughput volume at PV facilities, these path analyses are performed in seconds, according to Rudolph. Discover Solar also has alarming functions, which can be set to report out-of-spec operation automatically. It replaces slow, engineer-intensive statistical process control methods, such as SAS JMP or Excel programs, says Plisinski.

Rudolph is targeting process optimization and health monitoring with the software release. Discover Solar has been tested at a manufacturer, and testing is underway with different applications within the product’s scope. — M.C.