Category Archives: LEDs

November 2, 2012 – OLED revenues are currently being driven by display applications (e.g. smartphones), but there’s a new battleground slowly emerging: OLEDs for lighting applications where the technology could offer some advantages in design and efficiency for some applications — if panel makers are willing to make some sacrifices, according to a report from Yole Développement.

Conventional LED technology has paved the way in solid-state lighting, and has a large headstart; OLED has to overcome high costs and current lower efficiency, which are hampering market adoption and penetration. The firm sees OLEDs for lighting making initial inroads in specific lighting applications (automotive, general lighting) and in niche specialty and high-end lighting where it can offer some differentiation in design options. To crack more traditional lighting markets (commercial, office buildings, etc.), however, OLED technology will have to advance the technology and expand across different niche markets to achieve economies of scale and will decrease costs. Yole pegs this happening sometime in 2014, with the rise of larger substrates and better process control.

Pars Mukish, technology & market analyst for LED & OLED at Yole, then foresees an astonishing growth projection for OLED lighting panels: from a $2.8M market this year (2012) to nearly $1.7B by 2020, with general lighting applications representing more than 70% of that business.

OLED panels revenue for lighting applications. (Source: Yole Développement)

That won’t come easy, though. There are a number of materials and OLED structures being explored and in production, tweaked to improve performance and lifetime and also decrease manufacturing costs. Polymer materials for OLEDs continue to struggle (vs. small-molecule OLED materials) in demonstrating their capabilities to lower costs and improve performance to production-acceptable levels. Rigid glass is still the go-to substrate for OLED lighting panels, but work continues on other flexible OLED technologies including roll-to-roll processing, ultrathin glass, and encapsulation options.

To have a chance at fulfilling the aforementioned growth expectations for OLED lighting, OLED panel makers have to quickly identify the winning technology approaches and time-to-market strategies. "New business models are mandatory as the traditional lighting industry will be reluctant to integrate new technology as it could eat away at margins — OLED cost directly impacts the cost of OLED-based luminaires," points out Milan Rosina, Yole’s technology & market analyst for OLED & photovoltaics. The kicker: both the new OLED technology and its integration into production are brand-new to panel makers, who are unlikely to sacrifice existing LED lighting sales and complicate production just to deploy a new technology, he notes.

Thus the key to OLED technology’s future in more mainstream lighting applications, the Yole analysts say, boils down to how and when panel makers can establish vertical integration strategies and figure out how to push the new technology through existing distribution channels. And above all, find that "spark" niche market (or markets) that will pave the way to economies-of-scale, which will open up the conversations to convey opportunities and advantages for OLED technology in general consumer lighting applications.

October 23, 2012 – ProTek Devices says it is now offering individual unpackaged die for LEDs in wafer form, available as unidirectional and bidirectional electrostatic discharge (ESD) protection diodes.

The new LED die (<6 mils thickness) supports LED lighting voltage at 5V, with other voltages "to be introduced soon," ProTek noted in a statement. The bidirectional die (PLED508 and PLED511) and unidirectional (PLED508U and PLED511U) die have Ti/Ni/Ag back metal and Al/Cu top metal.

The PLED511 LED die has 200,000 diodes/wafer, while the PLED511U has 150,000 diodes/wafer; the PLED508 has 300,000 and the PLED508U has 340,000. All are available as probed good die in wafer form, delivered quartered, sawn, and mounted on blue tape.

In addition to LED lighting manufacturers, other applications for the wafers include digital display boards; automotive LEDs; backlight LEDs, and solid-state lighting. Minimum order quantities are the equivalent of five whole wafers (quartered).

FlexTech Alliance announced the completion of a development project with Etched in Time, Inc. (EITI), for a plasma etch system that is compatible with a wide array of roll-to-roll equipment.  The result of the project is a tool that can be used in the manufacture of a broad range of products including LED lighting or solar panels fabricated on plastic substrates.

The purpose of this FlexTech Alliance funded project was to create a plasma etching tool for dielectric films that offers a number of manufacturing advantages for flexible electronics. For example, plasma etching is cleaner than a wet etching manufacturing process due to the lack of chemicals to dispose after use. Additionally, incorporating the system into a roll-to-roll process allows large area and flexible products to be fabricated at low cost.

After the successful system development, the final step of the project was installation of the EITI plasma tool into the roll-to-roll flexible processing equipment at Binghamton University’s Center for Advanced Microelectronics Manufacturing (CAMM), where the follow-on work will take place of fine tuning processes with the new system for different materials.  

The new tool has gained commercial traction since the project completion. For example, a joint venture has been established between EITI and the Solar Product Lab (SPL) at Arizona State University to build and install a demonstration tool to etch silicon nitride for solar cell production.
“Not only will this project refine the manufacturing process of printed, flexible electronics through the continued work at CAMM,” commented Michael Ciesinski, CEO of the FlexTech Alliance. “Etched in Time has also been very resourceful using the results of this project and their design and build expertise to adapt the technology for commercial markets.”

Additional applications of the tool include texturizing a silicon surface during the manufacture of solar cells fabricated with multi crystal silicon, a material currently in wide industry use.

October 15, 2012 – Researchers at the National Institute of Advanced Industrial Science and Technology (AIST) and the Chemical Materials Evaluation and Research Base (CEREBA) say they have evaluated molecules within a sealed organic light-emitting diode (OLED) in operation using laser spectroscopy, measuring both selectively and nondestructively

Their work, published in August in Applied Physics Letters, involves a method improving upon a laser spectroscopic technique to measure molecular vibrations at the interface of an organic layer inside the OLED device — specifically, evaluating a signal enhancement phenomenon that occurs at the interface with a concentrated electric field.

The problem with evaluating OLED devices, as with many other types of sensitive electronics components: the method itself often involves destroying the device or impacting its performance (e.g. introducing contaminants). Measuring OLED device degradation, particularly in devices with multiple and overlapping internal layers, is particularly difficult — yet much more needs to be known about the inner workings of OLED layer degradation to learn how to extend the device’s lifetimes for application in displays or lighting.

Key to AIST’s work is using "sum frequency generation" (SFG) spectroscopy, which employs wavelength-tunable lasers to collect information on specific interfaces of organic substances in complex organic devices. Specifically it has pursued two-color SFG spectroscopy to measure vibrational changes at the surface and interfaces in a solid; one tunable visible laser would still collect signals from multiple organic lasers, but implementing two lasers creates a "double resonance" that can be used to enhance and isolate signals from a targeted organic layer. They also tweaked the SFG spectrometer to maintain measurement resolution even at 1/100 laser power of conventional SFG spectrometers.

"By investigating in detail the ‘fingerprints’ of organic layers in an OLED device, the alteration and degradation of molecules in the operating device as well as the change in the electric field inside the device can be elucidated," AIST explains. Their goal is to determine, at the molecular level, the driving mechanisms of OLED devices and their degradation — and also seek ways to apply the work to other organic electronics fields, such as solar cells and transistors.

CERERA was established at AIST specifically to establish design and manufacturing technologies for OLED materials and devices, including evaluation and analysis techniques.

Top: Schematic drawing of the structure of the multilayered OLED device and the directions of the incident and emitted lights used for SFG spectroscopy. Bottom: Spectral changes in an operating multilayered OLED device, with +8 V application (light emission), no voltage application, and –5 V application. (Source: AIST)

by Mark Danna, VP of business development, Owens Design

Continuing a series of columns for SST, Mark Danna from Owens Design highlights common mistakes that can cause an outsourced partnership to fail and detail a methodology for approaching an outsourcing agreement that can minimize the risk and costs involved and help ensure a successful partnership.

October 12, 2012 – One of the toughest things about getting started on a tool development design and build project is that in most cases the overall requirements for tool functionality and performance have not been focused yet. Nevertheless, the group tasked with tool development responsibility is told to get moving on the project because "we are already late." In fact, from the point of view of most of those involved, the picture of what is needed is still kind of fuzzy and none of the critical details are well-defined.

It is, however, possible to launch the project, get it off the ground, and make progress while still clarifying tool specifications and requirements. A disciplined phased approach to the program can resolve many of these open issues (technical, commercial and market-related) in the first phase of any project.

For example, at the start of most tool development projects there usually is a gap between desired tool functionality and target tool cost. The engineers want to design the tool to meet all potential market requirements and perform at the highest level. The marketing group wants a tool that meets a specific set of market requirements and can be produced at the lowest cost possible. Very early in the program a functional/cost trade-off analysis needs to be done — and well understood — by both parties before tool specifications and performance can be agreed upon and finalized. One of the most critical parts of finalizing the tool specification is to really understand how the functionality of the tool will be validated at the end of the program. Without an agreed-upon functionality test, tool performance cannot be validated and the specification is meaningless.

Unfortunately, not all tool functionality can be nailed down in the first phase of the tool development project. For some projects, it is standard procedure for final tool production launch to begin before the overall tool characterization has been completed. During this process, if overall tool functionality changes significantly, tool specification changes are the inevitable result and most likely will affect overall tool design. Going into this phase with a tool design that can accommodate a wide range of design parameters can minimize the risk of a total design restart. The trade-off, of course, is that this increase in functionality will most likely lead to an increase in overall tool cost. By thinking about these potential issues early on, it may be possible to minimize the impact of design-related change by having the ability to easily change the design to meet the tool requirements once overall tool functionality has been solidified.

A lack of clarity early on in design requirement can exist whether the project is handled as an in-house development project or is outsourced. If it’s an outsourced project, the selection of a design-and-build partner and its ability to help clarify and focus the development effort is critical to the overall success of the program. While there is always a desire in a tight economy to keep as many costs in-house as possible, the money spent engaging the right outsource design-and-build partner at the beginning is likely to end up benefiting the project budget long-term. Where a typical equipment OEM may produce a new tool every couple of years, a good outsource partner might go through this development process 10-20 times per year. As a result, this outsource design-and-build partner will have established and proven procedures that can take that fuzzy picture at the beginning of the project and put it into focus.

Time must be committed early in the development phase of a project to bring the fuzzy parameters into focus. Tool cost vs. functionality trade-offs must be well understood by all stake holders. By leveraging either in-house or outside expertise in project planning and management, as well as design input from the very beginning, one can end up saving a lot of time, money, and aggravation.

Mark Danna is VP for new business development at Owens Design.

October 10, 2012 – Azzurro and Epistar say they have achieved GaN-on-Si based LEDs utilizing Epistar’s high-brightness LED structures and Azzurro’s patented technology for 150mm GaN-on-Si. The joint project, completed in four months, transferred Epistar’s existing LED structures built on sapphire to the GaN-on-Si material system. The companies characterized the achievement as "one step further towards implementation in mass production."

Using templates with strain engineering, Azzurro’s technology enables epitaxy engineers to quickly transfer LED structures to GaN-on-Si, the company says. A patented and proprietary buffer stress management enables better homogeneity (<4 nm wavelength homogeneity) for LED epi wafers, helping to reduce binning and increase yield.

"We are very excited about the outcome of this joined exercise which has exceeded all expectations regarding speed and cost of migration. The success helps us to utilize GaN-on-Si which is a game changer for the industry," stated Epistar chairman Lee Biing-Jye. "The technology to enable the LED industry to tap into the advantages of the volume, cost-effectiveness, and maturity of silicon foundries is ready with our strain-engineered templates," added by Erwin Wolf, CEO of Azzurro.

The promise of GaN-on-Si is to match the performance of sapphire-based devices, but using silicon equipment long commercially proven in the semiconductor industry to scale up operations, boost yields, and ultimately lower costs. In fact, the semiconductor industry is progressing toward consensus on building-block standards for automating LED production on 6-in [150mm] wafers. Toshiba is planning to ramp LED production using GaN-on-Si 200mm substrates by year’s end, through a collaboration with Bridgelux.

imec, meanwhile, has its own research program to develop GaN-on-Si power devices on 200mm wafers. Last year it produced successful wafers, and has also developed the prerequisite fabrication process with standard CMOS processes and tools. (Days ago ON Semiconductor joined that imec program, as it builds a GaN processing line in Belgium.)

October 8, 2012 – Solvay Specialty Polymers USA LLC has extended its line of high-performance polyester compounds with a new version targeting light-emitting diode (LED) TVs with higher heat and light stability.

Seeking to reduce product costs, TV manufacturers are finding ways to reduce the number of LEDs by sending more amps through the devices to hike brightness. (Another cost-lowering strategy: go the other way and give up some brightness in LED backlit models.) This raises the junction temperatures, though, and some materials can’t handle the higher heat and light output, e.g. discoloring more quickly in applications such as reflector cups.

Solvay’s new "Lavanta" 5115 WH 011 high-performance polyester line of liquid-crystal polymers, is a 15% glass fiber-reinforced injection molding compound developed specifically for LED electronic packaging applications that utilize surface mount technology. It has high reflectivity (>95%) with excellent whiteness retention even after thermal and light aging, translating to better reliability for LEDs that operate at high junction temperatures — e.g. filling very thin-walled sections required for low-profile, side-view LEDs. It also offers dimensional stability due to its low moisture absorption and exceptional weld line strength, according to the company.

The company plans to expand the Lavanta line with an enhanced version possessing even greater heat and light stability for longer product life and reliability. In addition to LED TV applications, the material is targeted for general lighting for indoor and outdoor applications.

ON Semiconductor (Nasdaq: ONNN) has joined imec to collaborate on the development of next-generation GaN-on-Si power devices. ON Semiconductor is presently building a GaN processing line in its Oudenaarde facility in Belgium Oudenaarde, Belgium. The Oudenaarde facility, which was acquired from AMI Semiconductors in 2008, has over 40,000 square feet of clean room space, is located on a 10 acre campus, and presently produces 0.35 µm to 2 µm low, medium, and high voltage analog CMOS and BCD technologies on 6 in. wafers (150mm). Denis Marcon, product marketing manager for the power electronics and LED programs at imec said the goal was produce GaN-on-Si at the facility.

GaN is characterized by superior electron mobility, higher breakdown voltage and good thermal conductivity properties, making it useful for power and radio frequency (RF) devices which need high-switching efficiencies. Today, GaN-based power devices are too expensive for large volume manufacturing, as they are fabricated on small diameter wafers using non-standard production processes, according to imec.

Caption:  Imec’s power devices on 200mm CMOS-compatible GaN-on-Si

Imec’s research program is focused on developing GaN-on-Si technology on 200 mm wafers, as well as reducing the cost and improving the performance of GaN devices. Last year, imec’s research program successfully produced 200 mm GaN-on-Si wafers, bringing processing within reach for standard high-productivity 200 mm fabs. Moreover, imec developed a fabrication process compatible with standard CMOS processes and tools, the second prerequisite for cost-effective processing.

“As a top 20 global semiconductor supplier with a portfolio focused on energy efficient devices, ON Semiconductor has been researching GaN silicon technologies for several years,” said Hans Stork, senior vice president and Chief Technology Officer (CTO) at ON Semiconductor. “Partnering with imec will help strengthen our current market position and potentially assist us in adding a competitive leading-edge technology to our customer offerings. We look forward to collaborating with a broad consortium of like-minded companies on forward-looking research in this field.”

According to Rudi Cartuyvels, vice president of smart systems and energy technology at imec: “Extraordinary developments continue to emerge from our GaN-on-Si Affiliation Program, creating further inroads to drive down production costs The newest addition, of ON Semiconductor as a strategic program partner, further advances our collective expertise. Leveraging joint efforts will help us overcome the next hurdle toward economical volume manufacturing, ultimately bringing GaN power devices to the market.”

October 4, 2012 – When LCD TVs were first competing against plasma TVs, one key differentiating argument was their brightness. Typical TVs have brightness measuring around >400 nits (1 nit is roughly 1 candela per m2) deemed suitable for TVs typically viewed in a living room and at a distance, while plasma TVs’ full-white brightness is typically sub-200 nits. (<300 nits is more typical of computer/laptop screens)

However, the trend in LCD TVs is now swinging toward lower brightness, points out DisplaySearch senior analyst Jimmy Kim, in a new blog post. Most existing low-brightness TV models were small and targeted the secondary market, but earlier this year first trials began for low-brightness TV models, with low-cost direct LED backlighting, in the main segment of large TVs, he notes. The tradeoff in these sets sacrifices design and picture quality for cost: lower brightness for the LED component, and a thinner light guide plate. These efforts have reduced the cost gap between LED and CCFL backlights to <1.3×, so pricing is similar. (A spike in CCFL materials prices is another reason for the shrinking cost difference.)

Consumers have responded, and low-brightness LED-backlit TVs accounted for more than 10% of total LCD TV shipments in 2Q12. So TV makers are now planning more models with low brightness, even those using edge LED backlights. Most mainstream TV models are being designed with ~350 nits, and some entry-level models will be as low as 250 nits, to fend off the charge of low-cost backlight TVs (300-350 nits); soon the only 400-nit LCD TVs will be high-end models, Kim indicates.

Getting edge-lit backlight TV brightness down to 250 nits narrows the cost gap between them and CCFL models from 2× to 1.5×, which is still a bit higher than aforementioned gap between CCFL and direct LED backlighting. But the goal here, Kim notes, isn’t to offer another CCFL alternative — it’s targeting the same entry segment as low-cost low-brightness direct LED backlight TVs.

by Dan Tracy, senior director, SEMI Industry Research and Statistics

October 3, 2012 – Semiconductor manufacturers in Japan are either consolidating or closing fabs, and, in several cases, transitioning to a "fab-lite" strategy, all in a restructuring effort to meet the market challenges ahead. While device manufacturers are consolidating manufacturing operations and plan to outsource more wafer fabrication and package assembly to foundries and packaging subcontractors, a large installed fab capacity remains in Japan. Recent data for the year shows overall wafer area shipments into Japan’s fabs being the same as shipments into Taiwan.

By 2014, the total installed fab capacity Japan should increase slightly from about 4.5 million to 4.6 million 200mm equivalent wafers per month. Installed 300mm fab capacity is expected to increase from about 760,000 to 840,000 300mm wafers per month — representing, by region, the third largest 300mm fab manufacturing capacity base globally. Over the next several years, fab spending in the Japan market will be directed towards the production of NAND flash memory, power semiconductors, high-brightness LEDs, and CMOS image sensors.


Regional share forecasted for 2013 fab materials market. Total market size: $25.7 billion.

Overall equipment spending in Japan will likely range on the order of $4 billion per year. Expected NAND flash investments in 2013 could approach up to $2.5 billion. LED fab equipment spending is estimated to be $340 million next year. Finally, Sony is expected to invest about US$ 1 billion or more in its CMOS image sensor production.

Japanese equipment and material suppliers are leading players on the global semiconductor industry stage. It is estimated that Japan-headquartered equipment companies collectively capture about 35% share of the global semiconductor industry spending per annum. Like their North American and European counterparts, customers in the rest of the Asia Pacific region are the largest base for new equipment sales.

Chemical and other material suppliers in Japan are market leaders in the manufacturing of silicon wafers, III-V wafers, advanced chemicals, packaging resins, and packaging substrates. It is estimated that the Japanese material suppliers sales represent about 70% of the global semiconductor materials market, both fab and packaging.

Japanese suppliers showcase the latest products at SEMICON Japan 2012

Leading Japanese equipment and materials suppliers will exhibit at SEMICON Japan 2012 on December 5- 7, along with global key players, at the Makuhari Messe, Japan. Find the latest products and innovations this companies offer to customers globally that enable key technologies for the future including 450mm, EUV, TSV, power devices, and HB-LEDs to name a few. Also, the show will co-locate with a major photovoltaic show, PVJapan 2012 so you can connect to two major microelectronics industries in a single visit.

For more information, including registration and exhibition, visit www.semiconjapan.org/en.