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June 22, 2012 — A multidisciplinary research team at Massachusetts Institute of Technology (MIT) and the Universidad Autónoma de Madrid in Spain developed a new mathematical approach to simulating the electronic behavior of noncrystalline materials, with applications in organic light-emitting diodes (OLEDs), flexible printable organic (FPO) electronic circuits, and solar cells.

This mathematical technique, free convolution (a form of free probability applied to random matrices), has not previously been applied in physics or chemistry. It uses approximations rather than exact solutions, yet the resulting predictions match the actual electronic properties of noncrystalline materials with great precision.

The method takes a matrix problem that is too complex to solve easily by traditional mathematical methods and “approximates it with a combination of two matrices whose properties can be calculated easily,” without the complex calculations that would be required to solve the original problem, explained Jiahao Chen, a postdoc in MIT’s Department of Chemistry.

Simulating materials that lack an orderly crystal structure with random-matrix theory allows researchers to couple disorder in a material with its effect on electrical properties, Chen said. Typically, figuring out the electronic properties of materials from first principles requires calculating certain properties of matrices. The numbers in the matrix represent the energies of electrons and the interactions between electrons, which arise from the way molecules are arranged in the material.
To determine how physical changes, such as shifting temperatures or adding impurities, will affect such materials would normally require varying each number in the matrix, and then calculating how this changes the properties of the matrix. With disordered materials, where the values of the numbers in the matrix are not precisely known, this is a very difficult mathematical problem to solve.

Random-matrix theory’s probability distribution makes it possible to translate basic information about the amount of disorder in the molecular structure of a material into a prediction of its electrical properties.

While mathematicians have used such methods in the abstract, “to our knowledge, this is the first application of this theory to chemistry,” Chen says. The team also investigated why free convolution was so accurate, which led to new mathematical discoveries in free probability theory. The method derived for estimating the amount of deviation between the precise calculation and the approximation is new, Chen says, “driven by our questions” for the mathematicians on the team.

“Our results are a promising first step toward highly accurate solutions of much more sophisticated models,” Chen says. Ultimately, an extension of such methods could lead to “reducing the overall cost of computational modeling of next-generation solar materials and devices. There is a lot of interest in how organic semiconductors can be used to make solar cells” as a possible lower-cost alternative to silicon solar cells, Chen says. In some types of these devices, “all the molecules, instead of being perfectly ordered, are all jumbled up.”

The research is reported in the journal Physical Review Letters, to be published June 29.

The team included Chen, MIT associate professor of chemistry Troy Van Voorhis, chemistry graduate students Eric Hontz and Matthew Welborn and postdoc Jeremy Moix, MIT mathematics professor Alan Edelman and graduate student Ramis Movassagh, and computer scientist Alberto Suárez of the Universidad Autónoma de Madrid.

The work was funded by a grant from the National Science Foundation aimed specifically at fostering interdisciplinary research.

Courtesy of David Chandler, MIT News Office. Learn more at www.mit.edu.

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June 21, 2012 — To support the next cycle of LED manufacturing, tools such as MOCVD, plasma etch, lithography, and others must undergo cost efficiency and yield improvements, says Yole Développement. Trends include migrating to larger wafers, silicon substrates, and tools developed specifically for LED fab, rather than retooled from semiconductor manufacturing specs.

The light-emitting diode (LED) market experienced an unprecedented investment cycle in 2010-2011, according to Yole Développement. The LED chip cycle was driven by demand in liquid crystal display (LCD) backlights, anticipation of a general lighting market boom, and generous stimulus subsidies from the Chinese central and local governments. The resulting overcapacity situation will take 12-18 month to absorb.

The next investment cycle, driven by lighting applications, will start in 2013. Expect a more limited cycle due to improvements in fab equipment throughput and yields. To enable massive adoption in general lighting applications, significant technology and manufacturing efficiency improvements are still needed to reduce the cost per lumen of packaged LED.

Figure. LED front end equipment market revenue (MOCVD, lithography, dry etch, PECVD, PVD). SOURCE: Yole June 2012.

LED manufacturing equipment trends

Front-end LED manufacturing typically represents about 50% of the total cost of a packaged LED. LED structures and materials are undergoing performance, manufacturability, and cost improvements.

The metal-organic chemical vapor deposition (MOCVD) equipment market represents a $4.3 billion opportunity in the 2012-2017 period. MOCVD represents the single largest opportunity for front-end cost reduction in LEDs.

Additional equipment — lithography, plasma etch, plasma-enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD) tools — together represent a $650 million opportunity and will essentially follow a similar trend, with some exceptions. The emergence of LED-dedicated tools has already contributed significantly to cost reduction in lithography, plasma, and PVD processing.

The market for dry etching tools is still growing in 2012 due to increasing adoption for patterned sapphire substrates (PSS).

Most lithography tools will see decreased market as LED makers transition to larger-diameter wafers. The number of wafer starts will see a moderate increase initially but start decreasing in 2015, said Eric Virey, senior analyst, LED, at Yole Développement.

PVD equipment will also experience moderate growth during the next investment cycle.

E-beam evaporators have turned into commodities, with systems available from dozens of vendors at very low cost. But opportunities exist in promoting sputtering for indium tin oxide (ITO) deposition, and sputtering could also gain some traction in metal deposition if the industry adopts large-diameter wafers and moves from batch to single-wafer processing. Sputtering equipment could then offer improved cost of ownership.

Learning from the semiconductor industry

With close to 100 companies involved in front-end LED manufacturing, the industry is too fragmented to generate significant economies of scale. Yole predicts massive consolidation within 3 years (2012-2015), which should speed up process and tools standardization and allow better economy of scale.

LED manufacturing still uses methods that would be considered outdated in most semiconductor industries. Consolidation and emergence of LED “giants” will also facilitate and speed up adoption of manufacturing paradigms coming from the IC industry.

Adoption of silicon substrates for LED manufacturing rapidly move LED epiwafer processing into existing, highly automated and fully depreciated CMOS fabs. This would also give LED makers access to extended “process toolboxes,” which could pave the way for entirely new LED architectures.

Traditional large semiconductor equipment suppliers are mostly absent from the LED manufacturing equipment markets. For MOCVD, the tools are very different than the epitaxy tools used in mainstream semiconductor manufacturing. Designing and building such equipment requires significant and unique expertise that Aixtron, Veeco and Taiyo Nippon Sanso, the leading companies in the sector, have acquired through almost 2 decades.

Other front-end LED manufacturing tools are similar in essence to those used in mainstream semiconductor fabs. However, they often require a full redesign to deliver optimum performance and cost of ownership for LED makers. Smaller companies eager to capture opportunity in this niche market are now offering LED-dedicated tools with cost of ownership (COO) payoffs.

Yole Développement’s new report, “LED Front-End Manufacturing,” is dedicated to the LED manufacturing technology & equipment market, including MOCVD, lithography, dry etching, PECVD and PVD tools.

Companies cited in the report:

ACC Silicon, Accretech, Advanced Dicing Technology, Advanced System Technology (AST), Advatool Semiconductor, Aixtron, ALSI, Altatech (Soitec), AM Technology, AMEC, And Corporation, Applied Materials, APT, Arima, ASM Pacific Technology, ASML, Astri, Aurotek, Autec, Azzurro, Bayer, Beijing Yuji, Bergquist, Bridgelux, Bruker, Canon, Cascade Microtech, China Electronics Technology Group Corporation (CETC), Chroma, Corial, Cree, Crystal Applied Technology (SAS), Crystal Optech, Crystalwise, Dai Nippon Kaken (DNK), Dai Nippon Screen Mfg, Daitron, Delphi Laser, Denka, Disco, Dow Corning, Dow Electronic Materials, Dynatex, Edison Opto, Epiluxy, Epistar, Eplustek, ESI, Eulitha, EV Group (EVG), Evatec, Everlight Electronics, Fittech, Formosa Epitaxy (Forepi), Four N4, Fraunhofer IZM, FSE Corporation (Fulintec), Galaxia, GE, GloAB, Hans Laser, Hansol Technics, Hauman, Heliodel, Hitachi Cable, Huga, Hybond, Iljin Display, IMEC, Intematix, InVacuo, Ismeca, JCT, JPSA, JT Corp, Jusung Engineering, K&S, KLA Tencor, Lattice Power, Laurier, Laytech, LG Innotek, Lightscape, Lightwave Photonic, Litec, Loomis, Luminus Devices, LWB, Maxis Co, Merk/Litec, Mitsubishi, Mitsuboshi Diamond Industrial, Molecular Imprint, Momentive, Monocrystal, MPI, Nanoco, Nanometrics, Nanosys, Nichia, Nihon Gartner, Nikon, NN Crystal, North Microelectronics, Novellus, NTT, Nusil, Obducat, Oerlikon Systems, OP System, Optest, Opto Supply Ltd, Orbotech, Osram, Oxfrod Instrument Plasma Technology, Palomar Technology, Panasonic, Philips Lumileds, Phosphortech, Plasma-Therm, Procrystal, Proway, Puji Optical, QD Vision, QMC, Quatek, Rigidtek, Rose Street Lab, Rubicon, Rudolph, Samco, Samsung, Sanken, Semileds, Seoul Semiconductors, Sharp, Shibuya, Sino American Silicon (SAS), Sino Kristals Optoelectronics, Sino Nitride, Sky Technology, SNTEK, SPTS, Stararc, Sumitomo Chemical, Suss Microtech, Synova, Tainics, Taiyo Nippon Senso, Tamarack, Tecdia, Technology & Science Enabler (TSE), Tekcore, Temescal, TeraXtal, Toyoda Gosei, Transluscent, TSMC, Ultratech, Ulvac, Uni Via Technology, Ushio, Varian, Veeco, Verticle, Wacker, Waferworks, Wellypower, Wentworth Laboratories, Withlight, YCChem, Ying Lyu, Zeon Chemical.

Dr Eric Virey, holds a Ph.D in Optoelectronics from the National Polytechnic Institute of Grenoble. In the last 12 years, he’s held various R&D, engineering, manufacturing and marketing position with Saint-Gobain Crystals.

Tom Pearsall started the European Photonics Industry Consortium (EPIC). Before EPIC, he works among others for Bell Laboratories, Thomson/CSF and Corning. He is a Fellow of the American Physical Society, EPIC, and the IEEE.

Yole Développement provides market research, technology analysis, strategy consulting, media, and finance services. For more information, visit www.yole.fr.

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Day 2 of the 2012 TechConnect World Summit, Expo & Showcase opened with fifteen parallel sessions ranging from printed and flexible electronics to device modeling to green chemistry and water to nanotechnology for cancer diagnostics. The unifying theme for this conference is promising technology in search of funding and the opportunity for market validation.

Liyong Diao of Brewer Science described the fabrication and characterization of CNT inductors on flexible plastic substrates. The Brewer operation in Springfield, MO is focused on materials & process development for printed electronics. Both SWCNT and MWCNT have a maximum current density, electron mean free path and thermal conductivity several orders of magnitude higher than copper. The Brewer material is applied as a spray suspension of CNT, and thin films had a sheet resistance <1Ω/square. Multiple spray/dry cycles are used to build up film thickness to the target 10µm. The CNT film resistance is not temperature sensitive, but RLC circuit resonance was environmentally sensitive to parasitic capacitance.

T.H. Chang of U Wisconsin, Madison showed a printing transfer method for fabricating flexible graphene transistors. The graphene was conventional CVD monolayer grown on copper film. Transfer is accomplished by proper sequencing of the surface energies of the device substrates and the transfer substrates so that the material you want moves when and where you want it to move. 140nm channel devices were fabricated with e-beam lithography.

 

Jean-Pierre Simonato of CEA Grenoble (France) presented a highly flexible transparent film heater based on metallic nanowires. The devices works on Joule heating, P=V2/R, of Ag nanowires. The device provides high heating rates and stable steady-state temperature control at operating voltages ≤12V. Sheet resistance is <20Ω/o up to 80% transmittance at 550nm. Unlike ITO, the Ag nanowire film is highly flexible, maintaining low resistance even during crinkling. The material set can be used to fabricate thermochromic displays. Heating and cooling rates are dominated by the substrate material, but good repeatability in thermal cycling was demonstrated with all substrates used. The group believes a reasonable trade-off can be achieved between transparency, conductivity and cost with the Ag nanowire system.

Junghyun Cho of SUNY Binghamton talked about the growth of nanostructured ceramic films from liquid solution. Their process strategy focuses on low temperature processing, mimicking biological processes where applicable. A variety of materials and applications were demonstrated, as shown in the table, with film morphology and as-deposited density depending on deposition parameters in solution. Activity is underway to extend the material/process technology to dye-sensitized solar cells in which the dye is incorporated into the ceramic film layer.

Toivo Kodas of Cabot Corp. gave an overview of functional nanomaterials technology at Cabot. His primary mission is to find problems that require particles as part of the solution, since the corporate banner is that they are the world’s largest ($3B) pure-play nanomaterials producer. Complex metal oxides made by spray pyrolysis are finding expanded use in security applications based on their unique spectral signatures, as they are extremely difficult to counterfeit. Custom coatings on gold nanoparticles exploit the surface enhanced Raman effect for security applications at extremely low reporter particle concentrations.

Also read Conference Report: TechConnect, Day 1

 

June 20, 2012 — DELO introduced the DELOMONOPOX AD268 epoxy resin to meet the low-cost, reliable-attach needs of radio frequency identification (RFID) device makers. The anisotropic, electrically conductive adhesive provides fast cure at chip attach, and is designed for flip-chip RFID packaging, as well as other packaging applications.

DELOMONOPOX AC268 reliably bonds chips, which measure down to 400

June 20, 2012 – Marketwire — Pure-play foundry Shanghai Hua Hong NEC Electronics Company Ltd. and test equipment supplier Advantest Corporation (TSE: 6857, NYSE:ATE) co-developed a wafer-level, multi-site parallel test scheme for radio-frequency identification (RFID) semiconductor devices that meets industry-standard ISO 14443 guidelines.

RFID devices that comply with ISO 14443 standards are divided into two types: Type A and Type B, by the modulation/demodulation for the 13.56 MHz carrier wave. When in use, a proximity coupling device (PCD) sends a carrier signal at 13.56 MHz to the RFID device. The RFID device’s antenna receives the signal wave, which carries both transmitted data and the power that drives the RFID device. The RFID device then sends a return signal carrying response data back to the PCD.

Crosstalk among RFID devices during wafer-level testing can result in reduced production yields and low productivity. The foundry worked with Advantest’s T2000 test platform to develop a test solution that offers fast, accurate recognition and feedback for RFID devices. The result is a high-signal-quality, anti-crosstalk interface and an optimized algorithm within the test program to minimize the bit error rate and perform multi-site parallel testing.

This methodology is currently being used in mass production to test 32 RFID sites in parallel. Hua Hong NEC is seeing improved cost efficiency of volume-production testing and reduced bottleneck at RF test, with approval from the foundry’s key customers. Hua Hong NEC offers advanced production processing and test development capabilities for smart card and information security applications.

The companies are collaborating on a next-generation solution capable of 64-site parallelism.

Shanghai Hua Hong NEC Electronics Company Limited is an 8

June 19, 2012 — Plasma etch and deposition processing system maker Oxford Instruments Plasma Technology won an order for its recently launched PlasmaPro Estrelas100 deep silicon etch tool from the University of Toronto.

The PlasmaPro Estrelas100 deep silicon etch tool offers flexibility for R&D uses. It forms nano and micro structures via Bosch and cryo etch technologies in the same chamber. It performs smooth sidewall processes and high-etch-rate cavity etches without changing the chamber hardware.

UToronto will use the system in its Emerging Communications Technology Institute (ECTI) in the central micro- and nanofabrication facility, serving academic research and development needs, as well as training functions. Professor Yu Sun, Director of ECTI, cited the PlasmaPro Estrelas100’s equipment quality, performance and capabilities, as well as system support.

The PlasmaPro Estrelas100 will be used for collaborative research with strategic partners in key research areas, including nanotechnology and nanofabrication, photonic materials and devices, micro- and nano-electromechanical systems (M/NEMS), biotechnology, micro- and nano-electronic devices, integrated optics, and photovoltaic devices.

The Canada Foundation for Innovation (CFI) funded the purchase and commissioning of important tools including deep reactive ion etch (DRIE) and other tools for the Centre for Microfluidic Systems in Chemistry and Biology.

Oxford Instruments provides high-technology tools and systems for research and industry. The company designs and manufactures equipment that can fabricate, analyze and manipulate matter at the atomic and molecular level. Learn more at www.oxford-instruments.com.

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June 19, 2012 — The dynamic random access memory (DRAM) recovery is sustainable into 2013, say Barclays Capital analysts. DRAM benefits from a supply discipline that was bolstered by oligopoly/DRAM consolidation and the Elpida bankruptcy; robust demand growth from non-PC applications (server/mobile DRAM bit demand to exceed PC for the first time in 2013E); and potential for additional positives related to Elpida (Hiroshima/Rexchip converted to non-DRAM).

Figure 1. DRAM supply/demand. SOURCE: IDC, Gartner, Barclays Research estimates.

What is different from previous cycles? Barclays expects a less dynamic but longer-lived recovery given the oligopoly situation and technological difficulties in geometry migration; and server/mobile DRAM becoming the demand driver, supplanting PC, in 2013, offering a better growth profile and much less volatility.

The DRAM industry is becoming increasingly similar to the NAND industry, and will see an even more rational supply/pricing environment, once Elpida’s bankruptcy and asset sale are resolved. Barclays sees the Elpida situation as similar to SK Hynix’s stumble in NAND in H1 2009. Micron’s strategic choice post acquisition of Elpida could trigger an even better DRAM recovery. The best case scenario would be the disposal of Rexchip (7% of global capacity) and some of Hiroshima fab (10%) migrating to non-DRAM manufacturing, Barclays asserts. Also read: DRAM partially recovers thanks to Elpida bankruptcy 

Figure 2. Global DRAM wafer capacity status. Note: Based on 12-inch wafers. SOURCE: IDC, Barclays Research estimates

What does this mean for share price performance? The peak and the trough of the DRAM cycle will narrow as more demand comes from specialty DRAM, which has less inventory swing, being a more customized product; and more proactive supply control by top-tier manufacturers after becoming an oligopoly. Following a prolonged industry downturn, there are currently fewer players in DRAM market, reducing volatility.

The launch of Samsung’s Galaxy S III LTE, which may adopt 2GB DRAM (vs 1GB of 3G Galaxy S III) and Apple’s iPhone 5, which may adopt 1GB DRAM (vs 512MB iPhone 4S) will significantly boost mobile DRAM demand from Q3 2012, driving tight supply. The impact of DRAM content per box growth for just these two models offers the equivalent of 10 million units of additional PC demand (5% of total PC demand) in H2 2012, Barclays estimates. In servers, an incremental increase in content per server should offer the equivalent of 2 million PCs (1% of total PC demand).

Access the full report at http://live.barcap.com/PRC/servlets/dv.search?contentPubID=FC1829598&bcllink=decode

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June 18, 2012 – PRWEB — Daewon Innost achieved what it says is the light-emitting diode (LED) industry’s best thermal dissipation performance on its Glaxum LED Array family of chip on board (COB) modules. The proprietary Nano-Pore Silicon Substrate (NPSS) technology developed by Daewon Innost led to thermal impedance of 0.41°C/W.

Daewon Innost’s NPSS is created by applying semiconductor lithography to silicon wafers, allowing for 50µm-pitch interconnection between gallium nitride (GaN) LED chips; conventional metal-core printed circuit boards (MCPCBs) cannot drop below 300µm pitches. The COB modules are fabricated with high-efficacy, commercially available 1W LED chips. An LED chip supplier independently tested the modules.

“Our Glaxum module runs over 12°C cooler than the previous top performing COB module,” said Sungyuk ‘Stephen’ Won, CEO of Daewon Innost, noting that generally 1°C lower operating temperature = an extra 1000 hours of lifetime.

The Glaxum NPSS modules are available in models ranging from 3.5 to 100W. The models with lowest thermal impedance are Glaxum-MCL-GL-WC-020-002 (warm white) and the Glaxum-MCL-GL-CC-020-002 (cool white). Tested voltage and current value of Glaxum module is 16.6 V, 1.2 A, respectively.

Daewon Innost was founded in 2011 as a spin-off from Daewon SPIC, a leading company in the global semiconductor packaging industry, to focus on LED lighting. Learn more at http://www.dwinnost.com.

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ECTC


June 15, 2012

June 15, 2012 — San Diego, CA, hosts the annual ECTC (Electronic Component Technology Conference) every three years. Attendance at this year