May 16, 2012 — Semiconductor assembly equipment supplier Kulicke & Soffa (NASDAQ:KLIC) broke ground on its Singapore global headquarters expansion, near the current leased headquarters location. A state-of-the-art 30,000m2 facility in Serangoon will bolster the company
Category Archives: LEDs
May 14, 2012 — Light-emitting diodes (LEDs) are typically manufactured on sapphire (Al2O3) substrates, about 90% of the blue LEDs currently in production. Silicon carbide (SiC) substrates are used for virtually all the remaining 10% of blue LEDs.
Sapphire substrates will see 20-30% demand increase annually for LED fab. The supply of sapphire ingots will increase more than 20% annually, shows Displaybank. Sapphire substrates require a supply chain of sapphire ingot, or boule, growth equipment suppliers, single-crystal manufacturers, and substrate makers that cut sapphire ingots into wafers. One mega trend for the industry, in addition to capacity increases, is larger wafer diameters.
A constraint, says Displaybank, is the lumen efficiency of LEDs made on sapphire substrates. LED efficiency is defined as the multiplication of internal quantum efficiency and external light extraction efficiency. Typical LEDs glow at 60-120lm/W, which should improve to the 120-160lm/W range by 2015. Blue LEDs based on sapphire substrates are limited in efficiency, due to a lattice mismatch between the sapphire substrate and gallium nitride (GaN) LED materials — 16% or more. The smaller the lattice mismatch, the higher internal quantum efficiency can be.
Table. LED-use ingot material properties. SOURCE: LED-use Next-generation Ingot/Substrate Technology and Industry Analysis Report, Nov.2011, Displaybank.
| Material | Lattice mismatch (%) | Growth method | Strength | Weakness |
| Sapphire | 16 | Cz method, Ky, Slow cooling | Low price, chemical stability | Large lattice mismatch |
| GaN | 0 | HVPE, Ammonothermal | Homogeneous substrates | Difficulty in high-quality crystal growth, high price. Currently in basic research stage. |
| SiC | 3.5 | Modified Lely | Chemical properties similar to GaN | Price, difficulty in large substrate growth, patent (Cree) |
| ZnO | 2.2 | Hydrothermal | Small lattice mismatch, large substrate possible | Long research period, expensive equipment |
| Si | 18 | Czochralski | Low price, large substrate possible | Difficulty in high-brightness manufacturing |
Since sapphire is electrically an insulator, vertical-architecture LED chips are made by removing the sapphire from the chips once the epi process is finished. GaN and SiC substrates can be made conductive, thanks to precise injections of active ions. SiC, GaN, zinc oxide (ZnO) and silicon (Si) substrates are considered as the future LED substrates, thanks to low lattice mismatches.
Cree is currently producing epi-wafers using a SiC substrate. Gallium nitride wafers are expensive, currently used for laser diode manufacturing but not for LED manufacturing. ZnO substrates are less expensive compared to GaN ones, but suffer from volatility issues at high temperatures. LED manufacturing process temperatures must be kept low with ZnO wafers. Si substrates are relatively cheap, and benefit from the long process history of semiconductor manufacturing on Si. However, Si wafers currently offer lower brightness than sapphire-based LEDs. Several companies are developing Si technologies for LEDs.
Displaybank’s report, “Next-generation LED-use Ingot/Substrate Technology and Industry Analysis (Al2O3, GaN, SiC, ZnO)” covers growth methods for sapphire, SiC, GaN, ZnO single crystals and the substrate processing methods. It also covers commercialization efforts on new substrates, and improved sapphire-based LEDs. Learn more at http://www.displaybank.com/_eng/research/report_view.html?id=828&cate=2
May 14, 2012 — Barclays Capital analysts attended Lightfair International, a large, US-based general lighting tradeshow, and gleaned several trends in light-emitting diodes (LEDs) and organic LEDs (OLEDs) for lighting. Data presented at the show points to strong and steady LED lighting demand growth in 2012, though the LED lighting “inflection year” is still in the future.
While utilization rates are still relatively low in LED fabs, many chipmakers are reluctant to convert all of their backlighting-specific (BLU LEDs for display applications) LED tools to lighting-specific production, because they value yields honed for a specific design. Chipmakers told Barclays that they do not want to reconfigure metal-organic chemical vapor deposition (MOCVD) tools unless they are confident that this backlighting-specific production will no longer be needed. This suggests that anticipated LED lighting demand in H2 2012 and beyond will require more MOCVD tool orders, even without higher capacity utilization rates in LED fabs. Gradually improved MOCVD capex, in Q3 2012 and beyond, will be supported by a steady stabilization in LED supply/demand as 2013 approaches.
Barclays observed that LED chips still compete based on price, even among the Tier 1 LED makers, and further cost reductions are needed if margins are to survive. LED component price declines did moderate to an extent relative to last year’s price cuts, but the aggressive pricing trend continues, driven in part by end customers leveraging Tier 3 quality price points in China against Tier 1 and 2 LED makers. Until LED makers reach 80%+ effective yields in the fabs, the distribution of LEDs per run is fairly wide. Chips that do not meet their application’s specs are dumped on the market at a much lower price. Indeed, even in lighting-grade LEDs, there is “no rationality for price points,” according to 1 Tier-1 supplier. The good news for LED revenues is that unit volume growth is offsetting the price cuts.
The quality barrier between Tier 1 and Tier 2/3 LED suppliers continues to hold, with only ~10 LED makers that can reach 100lm/W efficacy levels in mass production, and meet Energy Star, UL, etc., specifications. In step with the luminous efficacy improvements at the chip level, system-level efficacy also continues to increase, with various troffers and luminaries already approaching 100lm/W. Korean LED makers are considering leveraging BLU LEDs for some lighting applications, like linear lighting and troffers, because specifications are similar. As a result, Samsung is becoming a major threat to Tier-1 LED suppliers, longer term, as it focuses on quality.
Also read: As LED patents run out, supply chain value will shift downstream
With LED lifetimes approaching 50K hours, LEDs are no longer the predictors of the lifetime of the full system, and the lifetime of the other components is becoming more prominent. Despite various certifications available, data on the lifetime and reliability at the total system level is still fairly limited.
While still in the early stages of development, OLED lighting was also being exhibited by several suppliers, with Philips and OSRAM appearing to be at the lead from an efficacy and product quality standpoint. Philips’ OLED lighting panels reached 25lm/W this year, with the company aiming for 60lm/W next year, driven by new developments in OLED materials (Philips using RGB stack with combination of phosphorescent and fluorescent materials); new developments in the glass substrate (adding reflective element to the glass composition); and advances in the deposition and processing technology. However, while reaching 60lm/W efficacy would be a big breakthrough, the key from there would be lumen maintenance, which is still very low for the OLED lighting panels currently available on the market. And while some companies suggested that OLED lighting is now moving from a designer/architectural application to a high-end lighting application, based on the product specs and the pricing, Barclays puts OLED lighting ~5-7 years behind LED lighting.
This year’s Lightfair was “almost entirely focused on LEDs,” said Barclays analysts. While LED dominance in new products at the booths is not yet indicative of end market penetration, it highlights the inevitability of LED lighting adoption in the coming years. Most lighting manufacturers and suppliers and LED makers alike see 2012 as a year of steady, strong LED lighting demand growth, though not yet an inflection. The biggest ramp in demand remains in segments where lighting is on for longer than 8 hours per day (streetlights, gas station canopies, retail, hospitality, warehouses). This is aided by the Federal Recovery Act spending on retrofitting public fixtures. Membership in the Solid State Street Lighting Consortium — a Department of Energy (DOE)-sponsored consortium of cities and municipalities looking to upgrade their lighting systems to energy-efficient solutions — has expanded to ~350 members from less than 100 last year. Payback periods for LED installs are compressing — for outdoor lights, LED systems have gone from 50-60% more expensive than non-LED lights last year to ~30-50% more. The payback for replacing non-LED luminaires in many applications is currently 2-5 years, sufficient to ensure funding for many commercial and industrial users. Utility rebates and government subsidies offered in various regions enhance paybacks further.
Many companies at Lightfair indicated that advances in LED chips and components, especially with regard to high efficacy, have lowered the cost of other components in a lighting system, driving down costs.
Learn more about Lightfair at http://www.lightfair.com.
May 11, 2012 – Marketwire — Bridgelux Inc., developer of light-emitting diodes (LEDs), and Toshiba Corporation, leading semiconductor manufacturer, reported a 1.1mm2 LED chip fabricated on an 8" gallium nitride on silicon (GaN-on-Si) wafer, emitting 614mW, <3.1V @ 350mA. This is the best-reported GaN-on-Si LED performance on an 8” wafer, according to the companies.
Silicon is a less expensive LED substrate than the traditional sapphire materials, and benefits from use in the established, high-volume semiconductor manufacturing industry. Bridgelux has a proprietary buffer layer technology that it claims creates results comprable to sapphire-based LEDs. In August 2011, Bridgelux reported a lumens/Watt (luminous efficiency) record for GaN-on-Si LEDs.
Bridgelux and Toshiba engaged in a joint collaborative agreement earlier this year for LED chips. Further development will target commercialization of the technology, noted Makoto Hideshima, EVP of Semiconductor and Storage Products Company, CPV of Toshiba.
Now, Toshiba is also making an equity investment in Bridgelux, to jointly pursue innovative solid state lighting (SSL) technology. Toshiba’s advanced silicon process and manufacturing technologies will be put to use on Bridgelux’s GaN-on-Si LED chip technology. In October last year, Bridgelux brought in $15 million in financing, following a $50 million Series D round.
The equity investment, coupled with Toshiba and Bridgelux’s development relationship, will help the companies “drive down the cost of solid-state solutions for the general lighting market," said Bill Watkins, Bridgelux CEO.
Bridgelux develops and manufactures solid-state lighting (SSL). For more information, please visit www.bridgelux.com.
Toshiba is a diversified manufacturer and marketer of advanced electronic and electrical products spanning digital consumer products; electronic devices and components; power systems, including nuclear energy; industrial and social infrastructure systems; and home appliances. Website: www.toshiba.co.jp/index.htm.
May 11, 2012 — The Innovation Award Laser Technology 2012 recognized 3D metal micro-structuring laser technology from Schepers, excimer laser design for OLED and LCD display fab from Coherent, and a laser brazing head technology from Precitec Optronik.
Stephan Brüning, responsible for R&D laser applications at Schepers GmbH & Co KG, was awarded the €10,000 Innovation Award Laser Technology 2012 prize at this week’s International Laser Technology Congress (AKL). His team was recognized for their work in "3D micro-structuring of large-scale metal surfaces for embossing and printing applications with high-power ultrashort-pulse lasers." Brüning also has been awarded the title of Fellow of both AKL and the European Laser Institute (ELI).
The 2nd place for the award went to a team led by Coherent’s Rainer Pätzel focused on excimer lasers for active-matrix liquid crystal display (LCD)- and organic light-emitting diode (OLED)-based flat-panel displays (FPDs). Coherent’s high-power 308nm excimer laser with pulse repetition rate of 600Hz and stabilized output power of 1.2kW provides fast cycle times for excimer laser annealing (ELA) on Gen-6 FPD panels, increasing throughput over typical Gen-4 tools. In ELA, a laser processes amorphous silicon (a-Si) into low-temperature polysilicon (LTPS), increasing electron mobility by more than 100x. The laser line beam has a final homogeneity of 1.8% to allow 10-20 overlapping irradiations of each location with the same fluence when scanning the substrate. Coherent’s state of the art cylindrical optics deliver a homogeneous line beam with dimension 750 mm X 0.4 mm for Gen-6 ELA, creating a display backplane with very homogeneous 50nm film of polysilicon of approximately 0.3um2 grain size providing 150cm2/Vs — 2 orders of magnitude higher than the electron mobility of an amorphous silicon backplane. The output power of 1.2 kW was achieved by spatially merging and temporally synchronizing two high-power UV-oscillators, each capable of 1 Joule energy/pulse and 600 Hz pulse frequency. The VYPER dual-oscillator laser platform (photo above) was combined with a novel beam delivery concept for beam forming, mixing, homogenizing and projecting the incoming laser beams into one homogeneous line beam.
Third prize went to a team led by Precitec Optronik’s Markus Kogel-Hollacher for a 3D-capable co-axial laser brazing head with integrated seam tracking.
The Innovation Award Laser Technology is a European research prize awarded at two-year intervals by the associations Arbeitskreis Lasertechnik e.V. and the European Laser Institute (ELI), conferred on an individual researcher or on an entire project group, whose exceptional skills and dedicated work have led to an outstanding innovation in the field of laser technology. The scientific and technological projects in question must center on the use of laser light in materials processing and the methods of producing such light, and must furthermore be of demonstrable commercial value to industry. Jury decisions are based on:
- Proven commercial benefit
- Innovative quality of the resulting laser beam source, laser manufacturing process or laser system
- Scientific / technological quality of the underlying research
- Creative approach to technology demonstrated by the designated individual or project group
- Importance of the contribution of the applicant’s work to the overall innovative process
More information about the awards and this year’s winners can be viewed at www.innovation-award-laser.org.
Article courtesy of our sister publication Industrial Laser Solutions. Visit http://www.industrial-lasers.com/index.html for more information.
May 10, 2012 — In light of “challenging industry conditions” in the light-emitting diode (LED) and photovoltaics (PV) manufacturing sectors, Applied Materials (AMAT) decided to restructure its Energy and Environmental Solutions (EES) segment, according to a Form 8-K filing.
While the restructuring focuses greatly on wafering systems for PV applications (see our sister publication, RenewableEnergyWorld.com for that story), Applied Materials’ roadmap includes “significant reductions in development activities for LED.” AMAT plans to support existing metal-organic chemical vapor deposition (MOCVD) customers — by and large LED makers — but will not be pursuing any new business, noted Barclays Capital.
Barclays lists Samsung, Silan, Toshiba, TSMC, Micron, and IMEC among Applied Materials’ MOCVD customers. However, analysts predict that Veeco and AIXTRON will hold enough market share (90%) in MOCVD to make other entrants minor players.
“Workforce-related actions will be finalized and implemented in accordance with local legal requirements and in consultation with employees and employee representative bodies, as required,” states AMAT’s Form 8-K filing on the EES restructuring. Approximately 250 job positions will be affected.
After AMAT’s Analyst Day in March, Credit Suisse analysts noted that the company had de-emphasized comments on MOCVD.
And one year ago, Barclays and Credit Suisse were skeptical about AMAT’s MOCVD prospects, deeming its entry a “miscalculation” in such a competitive market, where the company would not make “any traction.”
May 10, 2012 — Organic light-emitting diodes (OLEDs) emerged on the display scene recently, gaining adopters in small screen sizes like smartphones, and just moving into large-size displays like 55” televisions in recent months (LG Electronics made one in December 2011; Samsung Electronics came out with one at CES in January 2012). OLED offers better power consumption, light emission, and clarity than liquid crystal displays (LCDs)
As OLED adoption ramps up, mass production technology for large-area OLED is increasingly an issue that could prohibit OLED from gaining market share on LCD. In current OLED manufacturing, color patterning is achieved by fine metal mask (FMM) using thermal evaporation, and laser-induced thermal imaging (LITI), which can be limited to small-size panels. Manufacturers are now looking for color patterning technologies — from solution-based printing to laser imaging and layering white OLEDs with filters — that suit display production at Gen-8 fabs or larger.
Also read: OLED trends: Materials, color patterning advances and the display race
Samsung Mobile Display (SMD) is developing small mask scanning (SMS) technology, which improves FMM color patterning. Hybrid patterning system (HPS) technology combines LITI and FMM, and is currently under development. LG is working on a method that combines white OLEDs with color filters (WOLED+C/F).
Displaybank issued a Korean patent analysis report regarding the OLED color patterning technology, comprising research and analysis about the patents of foreign companies in Korea as well as the key patents of Korea-based companies. 495 patents relating to OLED color patterning technology were selected in the primary screening among a total of 2,532 raw data disclosed or registered by December 2011. 52 key patents regarding SMS, HPS, Ink-jet, and WOLED+C/F technology were then analyzed as large-area OLED color patterning technologies. Learn more at http://www.displaybank.com/_eng/research/report_view.html?id=855&cate=2
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May 9, 2012 – BUSINESS WIRE — GE Lighting (NYSE: GE) is introducing a 100W-equivalent light-emitting diode (LED) bulb, developed in East Cleveland, OH LED lab with Nuventix, LED cooling technology developer and the winner of GE’s ecomagination Challenge. GE invested in Nuventix, and licensed its patent portfolio, in 2011.
GE’s 27-watt Energy Smart LED bulb is in a standard “A-19” bulb shape, with 1600 lumens (60 lumens/watt), uniform omnidirectional light distribution, 3000K color temperature, and 25,000-hour life rating (22.8 years at 3 hours per day).
The bulb is manufactured with a proprietary synthetic jet technology enabled by Nuventix’ collaboration. Nuventix’ oscillating membrane, called a synthetic jet (an alternative to a fan), cools the LED chips and fits within the form factor of the A-19 bulb shape. Each subsystem — optics, electronics, thermals — must be “designed for miniaturization and cooperative performance,” says Steve Briggs, general manager of LED systems, GE Lighting. This technology provides a “clear path” to higher light levels and more energy efficiency.
The bulb will be in stores in 2013, and is debuting at LIGHTFAIR International in Las Vegas this week. GE’s existing portfolio of LED bulbs includes a 13-watt LED (60-watt incandescent replacement) and a 9-watt LED (40-watt incandescent replacement), as well as others in various shapes, wattages, and colors.
Nuventix provides thermal management for electronics. Visit www.nuventix.com.
GE Lighting develops energy-efficient solutions to light commercial, industrial, municipal and residential settings. For more information, visit www.gelighting.com.
May 9, 2012 — SEMI presented US Congressman Dave Camp (R-MI) with its 2012 North American Government Leadership Award at the annual SEMI Washington Forum. SEMI’s award recognizes policymakers who show leadership and support for the US microelectronics and photovoltaic manufacturing value chain.
Congressman Camp represents the 4th District of Michigan and has served in the House of Representatives since 1991. In 2009, Representative Camp became the Chairman of the House Committee on Ways and Means, which oversees all tax legislation in the House of Representatives.
SEMI cited Camp’s leadership in extending the research and development tax credit, and efforts to make that credit permanent; support for free trade agreements, including the passage of the U.S-Korea Free Trade agreement; and support of domestic solar energy and solar energy manufacturing.
The SEMI North American Government Leadership Award was established in 2004 to recognize policymakers in the United States that promote pro-innovation policies. Recipients of the award are selected by the SEMI North American Advisory Board, and the award is presented in conjunction with the SEMI Washington Forum, one of the organization’s annual executive meetings with elected legislators and Federal officials in Washington, D.C.
SEMI is a global industry association serving the nano- and microelectronics manufacturing supply chains. For more information, visit www.semi.org.
May 9, 2012 — White-light quantum dots (QDs) are cadmium selenide materials that convert the blue light of light-emitting diodes (LEDs) to a high-quality warm white light, in a similar spectrum to incandescent light. Vanderbilt University researchers have developed white-light quantum dots from discovery in 2005 (with fluorescent efficiency of 3%) to a fluorescent efficiency of 45%.
Quantum dots produce colors based on the size of the quantum dot particles — shifting from red to blue as the nanocrystal shrinks. Ultra-small quantum dots, containing 60-70 atoms, emit white instead of monochromatic light. Almost all of the atoms of these QDs are on the surface, making white-light emission “intrinsically a surface phenomena,” said Sandra Rosenthal, the Jack and Pamela Egan Chair of Chemistry, who directed the research.
The high efficiency is comparable to some commercial phosphors, said Rosenthal. It could be improved even further. Rosenthal expects white-light quantum dots to be used in some special lighting applications.
Current white-light LEDs offer 28-93 lumens/watt. If the enhanced quantum dots were combined with the most efficient ultraviolet (UV) LEDs, it would register a luminous efficiency of about 40 lumens/watt, said James McBride, research assistant professor of chemistry, who has been involved in the research from its inception. As UV LEDs are improved, the hybrid LED/QD combo would gain higher efficiency.
Instead of creating a material “shell” around the QDs, the researchers treated quantum dots with metal (acetate) salts, following a lead from University of North Carolina research. The salts produced an 8% brightness increase. Once the researchers determined that acetate salts had an effect, they tried acetic acid, which binds to quantum dots. The acetic acid treatment increased the quantum dots fluorescent efficiency to 20%. From there, researchers tried other members of the carbocyclic acid family. Formic acid, the most acidic and simplest, pushed the efficiency up to 45%.
The brightness increase shifted the peak of the color spectrum of the quantum dots slightly into the blue, which is a light spectrum many consumers find unpleasant with today’s LEDs. The researchers will use other methods to correct the color balance.
The researchers’ next step is to test different methods for encapsulating the enhanced quantum dots.
Other contributors to the study include graduate students Teresa E. Rosson, Sarah M. Claiborne and undergraduate research student Benjamin Stratton, who is now at Columbia University. The research is described online in the Journal of the American Chemical Society. The work was supported by a grant from the National Science Foundation.