ISG Illumination

Polycarbonate components simplify LED lamp design

Simon Speight — Tue, 15 May 2012 07:39:29 GMT

Market demand for energy-efficient lighting solutions has been rising rapidly, and LED lighting products are the focus for the next-generation of fixtures in architectural, commercial, industrial, and residential lighting. New materials are playing a pivotal role in the optimization of these LED replacement lamps and outdoor fixtures (Fig. 1), driven by the specific thermal and mechanical needs of LED lighting.

Fig. 1.

Several different grades of polycarbonate (PC), a type of thermoplastic, have been optimized for use as LED parts including reflectors, diffusers and lenses. PC reflectors provide a diffuse light from LED-based troffers, while PC-based heat sinks and PC lenses with ultraviolet (UV) protection can offer increased design flexibility to the manufacturers of LED replacement lamps and luminaires.

Polycarbonate vs. PMMA

The increasing adoption of LED lighting creates applications for polycarbonates that were previously the preserve of materials such as glass and metal. For instance, because LEDs emit “cold” light without infrared (IR) radiation, thermal stress on the lamp components is reduced, making it possible to replace glass lenses with those made of transparent thermoplastics, most notably polycarbonate and polymethyl methacrylate (PMMA). PC and PMMA have already been applied to LED lamps and luminaires, especially as parts of housings or transparent covers.

PC and PMMA components can be lighter and thinner than glass, and offer design flexibility. In addition, the components have been cost effectively scaled to production volumes using injection-molding processes. Relative to PMMA, polycarbonate benefits from greater heat resistance, higher impact strength and increased resistance to breakage. PC is also more flame-retardant. Benefits of PMMA over PC include its higher light transmission (> 92%) and better resistance to UV radiation.

Special grades of PC have a light transmission in the visible-wavelength range just under 90%, but they absorb radiation in the UV as well as mid- and far-IR regions. UV exposure will damage standard grades of PC, resulting in an increasing yellowness that impairs the transparency of lenses and covers for lighting fixtures. To counter this phenomenon, a new infusion process has been developed to concentrate UV protection at the surface of PC products (see sidebar).

PC lenses

If PC is to be used in LED lenses, its optical properties must remain unchanged after long-term exposure to LED light. Testing has been performed on 4-mm thick polycarbonate lenses exposed to commercial LED lighting with an intensity of 46 lumens per square centimeter for over 6000 hours at 90°C. Light transmission, clouding and yellowing values (yellowness index, ASTM E 313) changed little under these conditions.

FIG. 2.

A further advantage to polycarbonate in lens applications is its high refractive index, which allows thinner lenses to be fabricated. Bayer MaterialScience offers several polycarbonate grades that differ in viscosity, color and degree of UV protection, but transmission remains a function of PC thickness (Fig. 2).

PC grades can also be optimized for flame-retardant characteristics. For example, TerraGlo’s Alba Series of luminaires (Fig. 3) are designed with the driver circuitry and LED board underneath the fixture enclosure. As a result, the fixtures needed an enclosure material that was rated to the flammability standard UL94 5VA. The company selected a 3-mm transparent lens cover made from Makrolon FR7087 polycarbonate. The material has been tested by UL including glow-wire flammability and ignition testing.

Diffusers and reflectors

FIG. 3.

Often, a diffusing effect is needed to evenly distribute the light emitted by LEDs – to reduce glare or provide even backlighting. With PC, there are two ways to achieve a diffusing effect. The material can be made translucent by incorporating appropriate additives. In this case, diffusion strength and transmission depend greatly on the additive type and concentration. Alternatively, irregular, satined surface structures (grain size of 10 µm) can diffuse light due to refraction.

The diffusing effect is measured by using a goniophotometer to determine the half-value angle as defined in DIN 58161. This corresponds to the reflecting angle at which the luminance has fallen to half the light intensity passing through in a straight line from the diffuser component. The larger the half-value angle, the higher the light diffusion.

An additional advantage to PC-based diffuser components is that they can provide a single-piece alternative to multi-component film and lens systems, thereby simplifying lamp assembly.

In order for polycarbonate to be used as a reflector, it can be colored or light-reflecting pigments can be added to the material. This produces a product that reflects light diffusely.

FIG. 4.

A recent example of a commercial reflector is the Twelve LED troffer reflector that has been injection molded by Fraen Corporation’s Optics Division in Reading, MA. This reflector design uses Makrolon 6265X, a polycarbonate grade that is also flame retardant. The diffuse illumination from the reflector could also be applied to low-bay commercial and architectural fixtures.

If directed light from the LED source is required, a thin layer of metal can be applied to the surface of an injection-molded component. For example, the Makrolon and Bayblend (a blend of polycarbonate and acrylonitrile-butadiene-styrene copolymer) grades can reflect up to 95% of the incident light in such applications.

PC reflectors can be more cost effective than metal reflectors, which often require expensive, time-consuming processes such as vacuum coating or wet-chemical electroplating. As with diffusers, additional cost reduction can result from designing the reflector and adjacent components into a single component.

Polycarbonate heat sinks

PC grades with high thermal conductivity have been developed to act as heat sinks in LED retrofit lamps. For example, at the Strategies in Light show in February, Bayer MaterialScience demonstrated a functional PAR30 LED replacement lamp with a PC heat sink and PC lens. The TC8060 PC features a thermal conductivity of 22 W/mK. The material is flame-retardant, complying with UL 94 V-0 rating at a thickness of 2.5 mm.

When PC is used for heat sinks there is greater design flexibility than can be accomplished using aluminum. Components with non-traditional shapes and more complex geometry can be fabricated. With injection molding, the heat sinks also can be lighter and don't require rework.

Flat or rounded designs

In many cases, it can make sense not to use injection molding to make PC components for LED lamps and luminaires, but rather semi-finished products such as thin films or sheets.

FIG. 5.

PC films can be printed and are easy to shape and reinforce through back-injection with a thermoplastic. Such extrusion films can provide homogeneous, diffused light based on either the surface structure or light-diffusing particles in the polycarbonate matrix.

Reflector films can also be produced with appropriate additives. Makrofol LM 327 polycarbonate, for example, is just 250-µm thick and easy to thermoform, yet its light reflection is ≥ 97% (based on ASTM E 1331, against a white background). Diffuser and reflector films have great potential for use in the backlight units of LCDs (Fig. 4).

Light-directing films can also be made of polycarbonate. The required effect is achieved using a finely impressed grid of lines that also ensures good homogenization of the light. Applications include transparent covers for strip lighting and LED tubes. A newer application for PC films involves light-extraction films for organic LED (OLED) panels.

Solid polycarbonate diffuser sheets are compatible with flat cover designs. In some cases, modification of the color temperature is also possible. For instance, The Makrolon DX warm diffuser sheets convert cool LED light to a warmer light with a transmission of over 70%. The half-value angle is very high at more than 50°, which means that thin diffuser elements can be made. Possible applications of diffuser plates include large covers for LED street lights (Fig. 5), smaller LED indoor lamps and LED billboards or signposts.

Improved manufacturing of LED lenses

Polycarbonate lenses represent a current area of research and development. At Bayer’s Technical Service Center in Leverkusen, Germany, it is testing collimator lenses (Fig. 6), typically focusing lenses with free-form surfaces and asymmetrical geometries. One target application is automotive LED headlamps using a single-lens design. Today, LED headlamps are comprised of several separate components that are heavier than polycarbonate-based lenses.

FIG. 6.

One downside to injection molding of PC lenses with free-form surfaces is the very long cycle times, sometimes up to 20 minutes, to achieve high optical quality with low stress and high dimensional accuracy. To improve on this approach, the company has developed a multi-layer injection molding process combined with new techniques for dynamic mold-temperature control. The component is gradually assembled in several layers, resulting in shorter cooling and cycle times.

Multi-layer injection molding can result in improved component quality, lower yellowness index and less transmission loss. There are fewer defects such as shrinkage-related sink marks, for example, because a greater proportion of the shrinkage takes place during the premolding step. In addition, lower injection pressures result in lower internal stresses.

To further optimize the injection-molding process, modeling of the multi-layer process makes it possible to calculate the necessary adjustment of temperature-dependent factors that impact component quality, such as warpage, shrinkage, stresses, and creep behavior. The next step will involve the use of simulation to fully optimize PC component quality.

Conclusions

Advanced polycarbonate materials can bring desirable properties to LED lamp and luminaires, including design flexibility, low weight and UV protection. To date, indoor LED troffers, alternative heat sinks and LED street-light covers have been optimized using these materials.

As PC grades are optimized further for specific applications, increased design flexibility will be brought to the makers of LED replacement lamps and luminaires.

Europe says goodbye to 60W incandescent lamps

Time Whitaker — Fri, 02 Sep 2011 22:31:00 GMT

The European phase-out of low-efficiency lamps, which began two years ago, now encompasses clear 60W incandescent lamps.

Empty shelves loom for 60W lamps

From today, the 60W incandescent lamp will gradually become a thing of the past in Europe. This type of lamp can no longer be manufactured in Europe or imported into the region. However, the lamps can be sold until stocks run out.

The new regulation comes into force as a result of the Ecodesign Directive (2009/125/EC), which has already outlawed 100W and 75W incandescent lamps (in September 2009 and September 2010, respectively).

Specifically, the regulation coming into force today says that clear (transparent) lamps with a wattage level of 60W or above need to have an energy-label class of C or above (A is the highest, G is the lowest - see photo, below, for examples).

Lamp labels

This effectively eliminates standard incandescent lamps from the market. However, the class C requirement means that other more-efficient technologies (such as improved incandescent bulbs with halogen technology) can remain on the market. This was felt to be necessary because compact fluorescent lamps (CFLs) and LED lamps, while being much more efficient, can’t provide the same “type of light” as incandescents.

From September 2012, all clear lamps at all wattage levels will have to achieve at least class C. Also, since September 2009 there has been a requirement that all non-clear (also known as pearl, or frosted) lamps must be class A, which in practice means that non-clear lamps have to be CFLs.

In its current form, the Directive only applies to non-directional lamps, while further legislation will cover directional lamps. This is sure to be one of the issues covered in the upcoming Strategies in Light Europe conference in early October.

More information from the European Commission

The European Commission has a website devoted to energy-saving light bulbs, which contains some useful details, particularly covering the relevant legislation.

A section entitled “Why has the EU acted?” focuses principally on energy savings and on the benefits of CFLs. Another interesting source of information is the “Professional FAQ” document that can be downloaded from the Technical Background section of the website.

This document covers issues such as the alleged intrusion of Brussels into citizens' private lives, the risk of lamp shortages and factory closures, and the effect on lamps that are sold incoporated into luminaires. There is also a question about possible weakening of the measure’s impact caused by people stocking up on conventional incandescent bulbs – which is referred to as “hamstering.”

The EC has also implemented other changes. Since September 2010, lamp packaging should carry better product information to help consumers choose the best solution according to their needs. Lamp producers are obliged to mention the lifetime of the lamp in hours, the number of switching cycles the lamp is designed for, the color temperature, the warm-up time, the size of the lamp and whether the lamp can be dimmed or not.

About the Author

Tim Whitaker is the Editor of LEDs Magazine.

California implements new light-bulb laws

Tim Whitaker — Mon, 10 Jan 2011 07:24:13 GMT

California has introduced a new standard for 100W incandescent lamps, one year ahead of the rest of the USA.
A new federal law introduced January 1, 2011 in California sets standards for the energy efficiency of incandescent light-bulbs sold in the state.

The law, resulting from the Energy Independence and Security Act of 2007 (EISA), is designed to reduce energy use and associated pollution and make the United States less dependent on foreign sources of energy. It will save California consumers money with new bulbs that offer the same amount of light while using less power.

While the country will adopt this standard on January 1, 2012, California was given authority to implement the national standards one year earlier. It is estimated that this will avoid the sale of 10.5 million inefficient 100-watt bulbs in 2011, which would cost consumers $35.6 million in higher electricity bills, according to the California Energy Commission (CEC).

The standard in California states that a 100-watt bulb manufactured on or after January 1, 2011 must use 28% less energy (i.e. a 100-watt bulb may not use more than 72 watts) in order to provide the same amount of light (in lumens).

The standard does not affect the existing supply of incandescent light bulbs stocked in retail stores or incandescent light bulbs already in use.

New lighting technology has become more efficient than old-fashioned incandescent bulbs. Approximately 90% of the electricity used by traditional incandescent bulbs is wasted as heat instead of visible light. Replacing traditional incandescent light bulbs with more efficient halogen lamps, compact fluorescent lamps(CFLs) or LED bulbs will save consumers money while still offering same amount of light.

The new standard is technology neutral and allows consumers to choose among a variety of high-performance products for their replacement lighting. The CEC press release mentions halogen, CFLs and LED lamps.

In related news, the Environmental Protection Agency (EPA) has released a revised series of recommendations on how to deal with broken compact fluorescent lamps (CFLs) in the home.

A new standard covering 75W lamps will be introduced in California on January 1, 2012, and standards for 60W and 40W lamps will follow one year later.

More information on the changes is provided by the CEC and by the US Department of Energy.

Hotel SSL retrofit delivers 1.1-year payback

Maury Wright is the Senior Technical Editor of LEDs Magazine. — Mon, 10 Jan 2011 07:00:35 GMT

DOE Gateway demonstration project in a San Francisco hotel shows LED retrofit lamps deliver 70% energy savings and a quick 1.1-year payback period on the investment.

The US Department of Energy (DOE) has just released the final report from a Gateway LED retrofit lamp installation in the San Francisco, California InterContinental Hotel. Solid-state lighting (SSL) installed in hotel common areas in place of existing halogen lamps delivered 70% energy savings and a 1.1-year payback after accounting for the halogen maintenance/relamping costs.

Halogen lights in hotel lobby

The hotel retrofit focused on luminaires that were in continuous operation in areas including the registration-desk area, the elevator lobbies, near conference rooms, and guest-room corridors. The project included wall-grazing luminaires, mono-point track lights, and recessed adjustable downlights.

Before the retrofit, the luminaires used a combination of 20W and 30W MR16, and 75W PAR30 halogen lights. Those lights were replaced with 6W MR16 and 11W PAR30 LED lamps from CRS Electronics. The retrofit lamps were chosen based on color quality, lumen output, candela distribution, beam appearance, color consistency, and flicker characteristics according to the DOE report. Moreover the chosen retrofit lamps had to be compatible with the existing transformers in the downlights and track heads.

The retrofit lamps do not deliver the same level of brightness as the halogen lights that were replaced according to the report. But in areas such as the registration desk the halogen lights were always dimmed and not operated at full brightness. The LED replacements are actually brighter than the halogen lights when compared to the way that the hotel facilities staff had operated the dimmable halogen lights.

LED retrofit lights

The lights have been generally judged positively by the hotel staff. The report states, “User feedback indicated that the LED lamps delivered warm lighting that flattered interior finishes and skin tones, and duplicated the original lighting design intent without distracting glare or flicker.”

The retrofit project cost $19,396 for the lamps and the relamping labor. The report calculated the annual energy cost for the relamped area of the hotel to be $1,975. The calculated cost before the retrofit was $6,361. But the longer life of the LED lights significantly reduces maintenance relamping costs resulting in the 1.1-year payback reported by the DOE.

At the DOE report publication date, the LED lamps had operated for 3000 hours “without incident.” The test will continue and the DOE plans to remove a sample of the lamps at 3000 hour intervals for tests to document color and light output over time. That data will be added to the report as it becomes available.

Gateway is a DOE program that's administered by the Pacific Northwest National Laboratory. Earlier this year in a DOE webcast, Bruce Kinzey, Gateway demonstration program manager and senior research engineer at PNNL, said, "Gateway's purpose is to demonstrate new state of the art products in real world applications that meet the three criteria of saving energy, matching or improving illumination, and being cost effective for the user."

EPA releases final draft of Energy Star Luminaires specification

Tim Whitaker — Fri, 07 Jan 2011 07:14:00 GMT

The Luminaires specification now has an effective date of October 1, 2011.

The US Environmental Protection Agency (EPA) has released the Final Draft of the Energy Star Luminaires V1.0 specification. This now has an effective date of October 1, 2011.

The specification is available from the Energy Star Luminaires web page, which also carries comments on Draft 1 of the specification (released May 10, 2010) and Draft 2 (released October 4, 2010).

The Luminaires V1.0 specification will replace the Residential Light Fixtures (RLF, V4.3) and Solid State Lighting Luminaires (SSL, V1.2) specifications.

EPA expects to distribute the finalized Energy Star Luminaires V1.0 specification before the end of January, 2011. Stakeholders wishing to provide additional comments on the Final Draft should submit these to luminaires@energystar.gov by Friday, January 14, 2011.

As well as finalizing the Luminaires specification, EPA has been engaged in the revision of Energy Star Program Requirements for all product categories in preparation for third-party certification requirements which take effect on January 1, 2011. Details of those changes, including Revised Partner Commitments for Residential Light Fixture and Solid State Lighting Luminaire manufacturers, can be found at www.energystar.gov/testingandverification. Please note that beginning January 1, 2011, manufacturers seeking qualification of new product models must do so through an EPA-recognized certification body prior to using the Energy Star mark.

Changes from Draft 2

The Final Draft distributed today reflects changes resulting from the Draft 2 comments, subsequent industry discussions, and the third-party certification updates. Important modifications from Draft 2 to the Final Draft include:

Accent lights and cove mount luminaires, formerly included only in the residential scope, have been added to the commercial scope of the specification with the same performance requirements.

For solid state luminaires consuming 5 watts or less, the power factor performance requirement has been reduced to ≥ 0.5. This change reflects what is both broadly accessible and cost effective.

The modulation depth requirement detailed under Operating Frequency Requirements for solid state luminaires has been removed. EPA will continue to follow the work of various industry groups working to develop recommended practices to mitigate the potential for perceptible flicker and stroboscopic effects with this technology.

Three specific exceptions to the Ballast/Driver Replaceability Requirements have been added for luminaire types for which it is impractical to enable a consumer to replace the ballast or driver due to the small form factor of the luminaire. Where partners elect to take these exceptions, extended warranty periods are proposed.

Lighting Toxics Reduction Requirements have been further refined, with exemptions now detailed in the specification.

All Supplemental Testing Guidance has been refined to make reference to testing models of subcomponents, and sample size language has been updated to reference the number of units of each model that shall be tested. The guidance also now indicates that luminaires shipped without lamps and capable of operating multiple wattage lamps shall be tested using the highest wattage lamp type detailed on the packaging.

Luminaire models qualified prior to January 1, 2011 (or those submitted to EPA contractors prior to January 1 and subsequently qualified) will remain qualified until October 1, 2011. After this date, to remain on the Energy Star qualifying product list they must be certified by an EPA-recognized certification body to meet the Luminaires V1.0 specification requirements.

Luminaire models qualified after January 1 (i.e. certified by an EPA-recognized certification body) using the existing specifications and also meeting the Luminaires v1.0 specification requirements will be automatically added to the Luminaires v1.0 qualifying product list on October 1.

Philips Lumileds mass-producing LEDs on 150-mm wafers

Tim Whitaker — Wed, 05 Jan 2011 07:08:00 GMT

Lumileds says that it is now producing millions of GaN-based LEDs weekly on 150-mm-diameter wafers, allowing the company to increase its production capacity for power LEDs.

As LED manufacturers seek to increase capacity and yield and reduce cost, moving to larger-diameter wafers is seen as a key enabling step. While many LED manufacturers continue to use 2-inch wafers as the starting point for device fabrication, an increasing number already use 3- and 4-inch wafers. The next step is to transfer production to 150 mm (approx. 6-inch) wafers.
Philips Lumileds recently claimed that it is "the first power-LED manufacturer in mass production on 150 mm wafers." The company says it is now producing "millions of GaN-based LEDs weekly" on the larger substrates. Lumileds operates wafer fabs in San Jose, California, and Singapore.

“The addition of 150-mm manufacturing capacity to our existing capability leverages our epitaxy and wafer-fabrication technology excellence and gives Lumileds the capacity to produce billions of Luxeon LEDs annually,” said Matthijs Glastra, Executive VP of Worldwide Operations for Philips Lumileds.

Lumileds says it will continue its current wafer production while ramping production of its 150-mm capacity to meet increasing demand for high-quality, high-performance LEDs from the lighting, automotive, and consumer electronics segments.

“We expect that the pace of LED adoption will require all other manufacturers to follow our lead and adopt similar strategies," said Glastra. "Their challenge will be to achieve the high yields and quality levels that we have already demonstrated.”

Each 150-mm wafer has approximately four times the surface area of a 3-inch wafer, and nine times the area of a 2-inch wafer, and more than double the area of a 4-inch wafer. Geometrically, because of the need to fit square or rectangular LED chips onto a circular wafer, some material is lost around the edges of each wafer.

The move to larger wafers is more advantageous for larger chip sizes...but only if devices can be produced with the same performance and quality. Critical process steps include the uniformity and reproducibility of epitaxy (deposition of the LED material layers) across the large-diameter substrates.

Lumileds also points out that manufacturing on 150-mm wafers can offer further advantages for capacity expansion. The addition of new epitaxy systems running 150-mm wafers represents a lower capital expenditure to achieve the same capacity expansion compared with adding more systems that run with smaller wafers. “Some of the newer entrants to LED manufacturing require many more reactors to match our volume capacity,” said Glastra.

Other LED makers

Of course, Lumileds is far from being the only company to have worked with 150-mm wafers. Sapphire wafer supplier Rubicon Technology is currently delivering on a $71-million order for 6-inch wafers from an Asian company, believed to be LG Innotek. Rubicon says that its customer has been in mass production for several months using 6-inch material, although the LEDs are likely to be mid-power devices for LCD backlighting applications (in contrast with the higher-power Luxeon LEDs for lighting applications). Rubicon has several other LED customers for 6-inch sapphire, although none are in volume production yet.

Meanwhile, Cree announced in September that it is building a new 150-mm LED wafer production facility in Research Triangle Park, NC. The new production line is scheduled to be installed over the next several quarters with a target of having the first products qualified on this line by June 2011.

LED-based MR16 from CRS Electronics approved by utility rebate programs

isgadmin — Fri, 03 Dec 2010 03:20:00 GMT

Two major US utilities have approved an LED-based MR16 lamp from CRS for inclusion in their rebate program.

CRS Electronics Inc., a Canada-based LED lighting manufacturer, has revealed that two undisclosed major electric utilities in the US have approved LED-based MR16 lamps from CRS for an incentive program offered to their commercial customers. The CRS lamp currently is the only LED MR16 approved for such a rebate under their program.

Scott Riesebosch, president of CRS Electronics, explained that customers that qualify for the rebate in these regions will be able to purchase the CRS product at a small fraction of the regular cost. This will create "a substantial, solid value proposition for their businesses," he said.

CRS anticipates shipping product in the first quarter of 2011. Orders should start to be placed over the next month as the utilities roll out the program to their commercial customers.

"The quality and performance of our products continues to be our competitive edge," said Riesebosch. "Producing LED MR16 replacement lamps which exceed the performance standards prescribed by major utility suppliers for a rebate approval has always been a top priority at CRS."

The two unnamed major utilities service a combined area of more than 100,000 sq. miles in 40 counties within the continental United States. The opportunity for CRS to capitalize on these rebate programs was described by the company as "significant."

LED Japan/Strategies in Light conference report

admin — Fri, 12 Nov 2010 11:20:00 GMT

The third LED Japan/Strategies in Light Conference and Expo took place in Yokohama on September 29-October 1. The conference was a sold-out event attended by 190 people, with about two-thirds of the audience from Japan and the rest from other parts of Asia, as well as Australia, the US and Europe. Approximately 7,000 people (an increase of 40% from 2009) visited the exhibit area, which featured 90 exhibitors.

The conference was opened by Robert Steele of Strategies Unlimited, who reported that the LED market will reach $9.1 billion in 2010.

Energy savings

Based on several of the presentations from the Japanese speakers, it seems clear that Japan is very serious about the Kyoto Protocol and reducing greenhouse gas emissions. All the Japanese speakers stressed how Japan was doing to reduce carbon footprint, and in particular how LED lighting can aid in this effort. Detailed plans and measurements at national and local levels were presented. Presentations by European speakers also highlighted how LED lighting can help in this regard.

Fig. 1.

Both Alfred Felder of Osram Opto Semiconductors (see Fig. 1) and Junichi Nakamura of Shimizu Company discussed how to save 80% of power spent on lighting. Mr. Nakamura gave a detailed breakdown on how this 80% saving can be achieved in a typical office for 48 people at 5.25 m2/person. His calculations are as follows:

• 28% savings by direct 1-1 exchange of overhead fluorescent tubes to LED fixtures
• 27% savings by substituting overhead lights with combination of ambient + task lighting
• 5% savings through reduced lumen depreciation
• 10% savings by introducing day light with variable blinds + sensors to adjust amount of light in different parts of room relative to the windows
• 10% savings by using sensors to control lighting when people are absent from their desk which is about 30% of the time.

On top of the 80% mentioned above, since heat generated by LED is in the ceiling rather than the room, the power consumption of the air conditioning is estimated to go down by 12%.

Jianzhong Jiao of Osram Opto Semiconductors emphasized that the need for standardization is urgent for light engines. IESNA has a proposal on LED light engine measurements. The emergence of Zhaga, a global consortium for standardization of LED light engines, will hopefully speed up the market growth in the area.

Automotive applications

In the area of automotive lighting, Takashi Sato of Stanley Electric had an interesting observation about the cost of 1 kWh of electricity in cars as compared to household use. The former is ¥80 (US$0.97) while the later is ¥18-24 (US$0.22-0.29) in Japan. This makes the value proposition for using energy-efficient LEDs in automobiles relatively more attractive. While concept cars at car shows all have LED headlamps, at present, only about 0.1% of the cars use LEDs in this function. Besides cost, technical challenges such as heat, weight of the heat sinks, alignment of multiple LEDs and fog developing inside lamps are impeding the adoption process.

A member of the audience also commented on the serviceability of LED headlamps. When an exterior lamp goes bad in a car, the police are keen to give tickets and the speed of having that repaired is of the essence. Currently, one just buys a replacement lamp and the car is ready to go. While LED lamps do last the lifetime of the car, if there is a problem, there may be a long lead time to get the right parts for the particular car model and the repair will take longer and the labor cost will be high.

LED manufacturing

Fig. 2.

Srinivas Vedula of KLA Tencor pointed out that as the LED industry matures, it needs to import the discipline of the silicon industry. The use of process control is key. While 100% of substrate suppliers and most leading edge HB LED producers use process control tools, there is a great need to populate the tools among the next tier of HB LED manufacturers. Fig. 2 illustrates the benefits to be achieved from adopting process controls in LED manufacturing.

The US DOE estimates that a ~10X reduction in $/lumen is required for widespread SSL adoption within the next few years. About ~2X (50%) reduction is possible with better process control enabling:

• Baseline yield improvements,
• Faster excursion detection
• Faster process development and ramp into production

Moving forward, technology changes are resulting in new inspection requirements.

Chip size

One of the ongoing debates in the industry is whether a large chip or multichip package is good for applications that need high lumen SSL products. These applications can include general lighting like PAR38 retrofit lamps, track lights, street lamps, and specialty lighting such as projection display, automotive headlights, entertainment, UV curing, endoscopy, etc.

Fig. 3.

Chuck DeMilo of Luminus Devices compared the two types of packages (see Fig. 3). By using a single chip, one can create a single uniform shadow and eliminate “multi-source shadowing”. With the light guide closer to the source, there is better color mixing and uniformity. In the design of light fixtures, the aesthetics is better with one chip vs. multiple chips. Technically, DeMilo claims that a large chip reduces the current density (droop) while enabling high lumen packages with high efficiency. There is also cost savings because the optics used are less complex.

Next year

LED Japan/Strategies in Light 2011 Conference and Expo will take place in Yokohama on September 28-30.

LED Japan/Strategies in Light is part of the global Strategies in Light conference series, which also includes events in the USA, Europe and China.

About the Author

ELLA SHUM is the Director of LED Research at market research firm Strategies Unlimited.

This article was originally published here: LINK

Strategies in Light Europe addresses market adoption of LED lighting (MAGAZINE)

admin — Fri, 05 Nov 2010 10:20:00 GMT

With the theme of Accelerating the Market Adoption of LED Lighting, the inaugural Strategies in Light Europe conference took place in late September in Frankfurt, Germany. A total of 23 presentations were accompanied by two workshops, one on Standards and the other entitled “Building the Perfect Luminaire.” As described on p. 9, Strategies Unlimited’s Vrinda Bhandarkar presented an LED market overview and forecast. Another highlight was McKinsey’s presentation entitled “Country Road or Expressway: LED at the Crossroads” – see the article on p. 31. Presentations not covered in this article will be discussed in one or more follow-up articles to be published on our website.

Martin Goetzeler, CEO of Osram GmbH opened the main conference by discussing the decision makers who are shaping the future of light and are asking questions on two main subjects. “These are how can we save energy, and how can we optimize the quality of life,” he said. “LED lighting contributes to both in a significant way.”

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This article was published in the November/December 2010 issue of LEDs Magazine. To read the full version of this article, please visit our magazine page, where you can download FREE electronic PDF versions of all issues of LEDs Magazine. You can also request a print copy of LEDs Magazine (available by paid subscription) and sign up for our free weekly email newsletter.

About the Author

Tim Whitaker is the Editor of LEDs Magazine

This article was originally published here: LINK

LED momentum builds at annual Street and Area Lighting Conference (MAGAZINE)

admin — Wed, 03 Nov 2010 15:18:00 GMT

In late September, the Illuminating Engineering Society (IES) held the annual Street and Area Lighting Conference (SALC) in Huntington Beach, California with a crowd of more than 600 attendees focused increasingly on LED-based street lights. Attendees from utilities, municipalities, lighting manufacturers, and design houses shared information on how to successfully migrate to energy-saving SSL technology. Moreover, the presentations made it increasingly clear that SSL can deliver superior lighting despite obstacles that still must be overcome.

The most compelling presentations at SALC were all focused on actual LED street light installations. Californian cities including Huntington Beach, Los Angeles and San Jose made presentations, and we’ll get into some of that detail shortly. Moreover, both the Electric Power Research Institute (EPRI) and the Climate Group’s LightSavers Global Consortium presented trial data. The exhibits at SALC are limited by the IES to a relatively small area, but LEDs also dominated that space.

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About the Author

Maury Wright is the Senior Technical Editor of LEDs Magazine.

This article was originally published here: LINK

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About the Author

Maury Wright is the Senior Technical Editor of LEDs Magazine.

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About the Author

Maury Wright is the Senior Technical Editor of LEDs Magazine.

LEDs dominate presentations at annual Street and Area Lighting Conference

admin — Tue, 12 Oct 2010 15:22:00 GMT

The Illuminating Engineering Society (IES) held the 2010 Street and Area Lighting Conference (SALC) in Huntington Beach, California in late September and LED-based solid state lighting (SSL) was the focus of the majority of the presentations. The scheduled also included comparisons of different lighting types and a couple of reality checks presented by lighting designers.

The first reality check came early in the program on Monday morning when Lighting Design Alliance President Chip Israel presented “No Mo’ Pole Ploppin’.” Israel challenged several concepts that the outdoor lighting industry has largely accepted as true such as SSL is always more efficient and light trespass is always bad.

Israel’s points were clear that lighting must match the application at hand. Sometimes light trespass on a sidewalk or washing a wall along a sidewalk creates a safer and more inviting environment without any negative impact. And he showed how even incandescent lights can be an energy-efficient and long-life choice in some outdoor applications when the designer chooses low-wattage lamps and adds dimming control to extend lamp life to the 50,000 hour range.

Israel has certainly done his share of LED projects as well and is a proponent of SSL used correctly. He even pointed out that we may be lighting the wrong things with street lights in some cases. To prompt thought, he asked whether lower-power near-ground lights such as those used along airport runways might be superior to lights mounted high on poles in some cases.

Most presenters, however focused on SSL and that seemed to be the topic that most in the crowd were interested in learning more about. The program and a number of presentations focused on LED street-light installations including some data on performance and cost.

SSL Street light trials

The cities of Huntington Beach, Los Angeles, and San Jose all presented papers on their SSL street-light projects. Moreover, the Electric Power Research Institute (EPRI) and The Climate Group’s LightSavers organization presented information on multiple trials in which they are involved.

Highlights of the trial data came from Los Angeles – the largest SSL street light installation in the world. Ed Ebrahimian, Director Bureau of Street Lighting in Los Angeles, reported that the city has installed 30,000 SSL street lights out of the 140,000 they plan to retrofit with LEDs. The city is spending just under $500 per light replaced with LEDs including the cost of material, labor, and engineering. Ultimately the city hopes to save $10 million annually in energy and maintenance savings.

The city of San Jose, CA has undertaken a much smaller trial but delivered some very interesting results. The city worked with the Virginia Tech Transportation Institute to measure both light levels and the ability of humans in a moving vehicle to detect objects under different types and levels of light. Consultant Nancy Clanton reported that the LED lights operating at lower power than legacy lights produced superior object recognition results, and Clanton attributed the LED advantage to the fact that LEDs produced white or broad-spectrum light.

LED alternatives

Of course not everything was all about LEDs. Ronald Gelten of Philips Lighting presented “Blinded by the lights” that covered the basics of how LEDs and other types of lights operate and the relative advantages of each. Gelten has developed a series of pentagonal-shaped graphs that present the attributes of various lighting types on five axes. For example, he has a cost comparison that incorporates payback time, initial cost, energy savings, replacement cycles, and preventative maintenance.

Indeed Mohammed Rashed, Chief Engineer of Electricity from the city of Chicago, Illinois, presented a case study on why the city is installing ceramic metal halide (MH) street lights. The MH alternative fared better in Gelten’s cost analysis even though pilot tests in Chicago indicated a preference among residents for LEDs.

The week concluded with a move north into the city of Los Angeles where a number of people toured parts of the LED installation there accompanied by Ebrahimian. The tour provided a clear demonstration that SSL delivered a more even light distribution with no bright or dark spots relative to high-pressure sodium (HPS) lights.

In addition, the DOE Municipal Solid-State Street Lighting Consortium held its first workshop in Los Angeles on Thursday after SALC ended. Much of the material at the workshop mirrored presentations from SALC. But Mark McClear, Director of Business Development at Cree, made one surprising point. Cree has LEDs running in the lab that have maintained L70 performance for more than 100,000 hours. Tongue in cheek he suggested LEDs last forever in ideal conditions. But McClear also pointed out that Cree had replaced the drivers in the long running LED test -- making the point that reliable SSL is a system-design problem.

Make sure you peruse the November issue of LEDs Magazine. We’ll have a more detailed report on SALC in the issue.

About the Author

Maury Wright is the Senior Technical Editor of LEDs Magazine.

This article was originally published here: LINK

LED market to reach $9.1 billion in 2010, reports SIL Europe

admin — Mon, 04 Oct 2010 15:25:00 GMT

The latest LED market numbers from Strategies Unlimited show that total sales of packaged LEDs are expected to grow by an amazing 68% in 2010, reaching $9.1 billion.

SIL Europe 2010

The new forecast was revealed by Strategies Unlimited’s Vrinda Bhandarkar at last week’s Strategies in Light Europemeeting in Frankfurt, Germany, which had a registered attendance of more than 600 visitors from 44 countries.

Despite fears of an industry slowdown in some quarters, Strategies Unlimited has raised its forecast for 2010. In February this year, the market research firm predicted that the LED market would grow 52% in 2010 to reach $8.2 billion.

Looking forward, Bhandarkar said that the industry would experience a compound annual growth rate (CAGR) of 27.8% from 2009 to 2014, to reach $18.4 billion.

LED backlights for LCD TVs and monitors will be the biggest growth driver, said Bhandarkar. The slowing LCD TV market may reduce projected shipments of LED TV backlights, but the penetration of LEDs will continue to increase.

Meanwhile, the penetration of LEDs into the lighting market has achieved substantial momentum. “We expect this momentum to pick up speed in 2010, with a growth rate of 34% compared to 31% in 2009,” said Bhandarkar. Outdoor lighting and replacement lamps will be the fastest-growing segments. The longer-term outlook continues to be highly positive, with a 5-year CAGR forecast of 48%.

The same results were also presented by Strategies Unlimited’s Bob Steele at last week’s LED Japan/Strategies in Light conference and exhibition.

Strategies in Light Europe

The first Strategies in Light Europe event featured a strong conference program over three days, including two workshops, one discussing standards and the other looking at key considerations for building the perfect LED luminaire. A total of 38 companies participated in the exhibit.

The well-attended Keynote session featured Martin Goetzeler, President & CEO of Osram, along with Jan Denneman, President of the European Lamp Companies Federation (ELC), and John Magan, Deputy Head of Photonics Unit G5 of the European Commission (EC), who spoke about the role of solid-state lighting in the Digital Agenda for Europe.

Among many other highlights was a well-received presentation from Wu Ling, General Secretary of the China Solid State Lighting Alliance, who spoke about her country’s desire for cooperation on an international scale. Of course, the Chinese market is already immense; around 1.05 billion LEDs were used in Various installations in the Shanghai World Expo, for example. Also, a municipal showcase project involving 21 cities around China has already seen the installation of 1.7 million LED fixtures, and has resulted in an energy saving of 0.16 billion kWhr.

OLED luminaire from Osram

A detailed review of the presentations at SIL Europe will be published in the Nov/Dec issue of LEDs Magazine.

Tim Whitaker, SIL Europe Conference Director and Editor-in-Chief of LEDs Magazine, was very pleased with the quality of the speakers and the level of discussion generated by the presentations. “The European lighting industry is heavily involved in the transformation to LEDs and other energy-efficient lighting technologies,” he said. “However, this transition is still at an early stage, and there are many important areas that require in-depth discussion, for example the development of standards, the role of the European Commission, and the importance of market segments such as modules and retrofit lamps. The conference presentations covered these and many other subject areas, and we expect that Strategies in Light Europe will develop into an important forum for debate in the years to come, as the industry continues to develop.”

Next year, Strategies in Light Europe will take place on October 3–5, 2010 at the Crowne Plaza Milan Linate in Milan, Italy.

This article was originally published here: LINK

Street lighting and LEDs are key areas of focus at SALC

admin — Wed, 22 Sep 2010 15:28:00 GMT

As the only event in North America that specifically targets the needs and concerns of the street and area lighting industry, next week’s Street and Area Lighting Conference (SALC) event is certain to feature extensive discussion of LED-based solid-state outdoor lighting. Organized by the Illuminating Engineering Society (IES), SALC takes place on September 26-29 in Huntington Beach, California.

Dawn Mitbo of Puget Sound Energy, the SALC Committee Chair, welcomes the industry, municipalities, specifiers and utilities to attend, stating, “Last year’s conference in Philadelphia was very well attended and we will be offering more of the same top quality presentations in Huntington Beach. This conference is a great opportunity to network with many hundreds of your peers, attend presentations by leaders in our industry, and walk an extensive exhibition area where all of our leading manufacturers [over 40 companies] will be happy to discuss products and trends.”

LED-related conference presentations and sessions include:

“City of Los Angeles – Changing our Glow for Efficiency,” presented by Ed Ebrahimian of the City of Los Angeles
“San Jose Case Study” presented by Nancy Clanton of Clanton & Associates and Laura Stuchinsky of the City of San Jose
“CalTrans: Informed LED Purchase Decisions,” presented by Gonzalo Gomez of CalTrans
A “Utility LED Tariff Panel”
“Blinded by the Lights,” an LED presentation by Ronald Gelten of Philips
“LED Specification and Design Fundamentals” presented by Cree’s Mark McClear
“The Adoption of New Technology into an Old Culture,” presented by Ted Konnerth of Egret Consulting Group, who also spoke this year at PennWell’s Strategies in Light.

This year, The Climate Group will not only be presenting its global LightSavers program on the conference agenda, but attending with a large delegation of international attendees representing the municipal programs and projects in Asia, Australia and India, as well as New York City and Toronto. This is the first time that an international delegation or even individuals from countries outside of the United States and Canada will have attended SALC.

Philip Jessup, Director, Cities and Technology, The Climate Group will present “LightSavers: A Global outdoor LED Trial.” The LightSavers initiative is a global trial of LED street and parking area lighting aimed at accelerating use of LEDs and smart controls in 10 large cities on four continents, including London, New York, Toronto, Sydney, Tianjin, Mumbai and Kolkata. This session will lead a discussion of interim results from several of the trials.

Delegates will also meet exhibitors directly, facilitated through a introduction and matching event. Each exhibitor requesting to meet with the delegates will make a brief introductory presentation. Much like “speed dating” in “elevator pitch” format, the objective is make a good first impression, be interesting and sincere, and see where there is common interests, all with the objective of having another meeting.

Delegates will depart from the conference and head to Los Angeles for a city installation tour hosted by Ed Ebrahimian, director, Bureau of Lighting of the City of Los Angeles and Christopher Ruud, president of Ruud Lighting. This will be followed by a trip to San Jose for another presentation and tour of the LED streetlight and lighting controls trials hosted by Laura Stuchinsky, Sustainability Officer, City of San Jose and Amy Olay, San Jose Department of Transportation. While in San Jose, they will also tour the Philips Lumileds facility with an opportunity to see LED chips being manufactured and to discuss quality and technical issues with Lumileds staff.

Following on from SALC, the DOE Municipal Solid-State Street Lighting Consortium is hosting its first Annual Meeting on September 29. This meeting enables attendees to learn more about Consortium committee efforts related to developing model guidelines, launching regional education workshops, initiating the first Consortium demonstrations, and establishing interchange between related efforts and organizations.

About the Author

Brian Owen, a contributing editor of LEDs Magazine, is also the Program Advisor to greenTbiz, which facilitates the LED City Toronto initiative. He is actively involved in the development and operation of energy conservation programs for government, municipalities and utilities and specializes in capacity building, commercialization and market transformation. greenTbiz, an ENERGY STAR, Lighting Facts and L Prize Partner, provides energy conservation and environmental awareness programs to the small business sector in Toronto, Canada.

This article was originally published here: LINK

LED manufacturing tools and research partnerships headline at Semicon

admin — Fri, 16 Jul 2010 15:53:00 GMT

The Semicon West tradeshow took place in San Francisco, CA this week, and LEDs were a huge presence at the event that is focused on IC manufacturing. The conference sessions included a full-day program focused on more-efficient HB-LED manufacturing, and manufacturing tool vendors used the tradeshow as a venue to launch new products. Research specialist Imec, meanwhile, added Micron Technology, Applied Materials, and Ultratech to its GaN-on-Si (gallium nitride on silicon) research program.

LED manufacturing tool announcements came from Veeco Instruments, Palomar Technologies, and EV Group. Veeco announced a new member of its ContourGT Optical Surface Profiler product line. HB-LED makers use the quality-control-centric products to characterize patterned sapphire substrates (PSSs). The new ContourGT-X8 PSS combines Veeco's metrology hardware and software with a new non-contact 3D measurement capability to enable high-throughput, repeatable characterization of PSSs.

"With the rapid growth of PSS as a vital technology for enhancing efficiency and ensuring color consistency in HB-LEDs, measuring their feature size and consistency on sapphire wafers is becoming a critical step in HB-LED manufacturing," said Mark R. Munch, Ph.D., Executive Vice President, Veeco Metrology & Instrumentation. “Now, the ContourGT-X8 PSS gives wafer suppliers and HB-LED device manufacturers an affordable way to obtain high-throughput, 3D surface metrology to enhance productivity, while assuring the quality of their end products.”

Automated wafer bonding system

EV Group used Semicon to announce what it proclaims is "the industry's first fully automated wafer bonding system for HB-LED manufacturing." The EVG560HBL wafer bonder can handle multi-substrate bonding and sustain throughput of 160 binds per hour. The tool clearly targets the fact that demand for LEDs continues to lead supply and the new design will allow manufacturers to increase capacity and yield according to the company.

"Leveraging our 30 years of experience in developing wafer bonding solutions for advanced micro-electronics manufacturing, the EVG560HBL is the latest result in our ongoing efforts aimed at helping HB-LED manufacturers develop more efficient, cost-effective and higher yielding devices to meet the demands of their customers," said Paul Lindner, executive technology director, EV Group.

In a different area of bonding, Palomar Technologies announced a new fully-automated wire-bonding and die-attach tool that targets HB-LEDs as well as other semiconductor components. The 3800 Ultra Flexible Die Bonder offers 3.5-micron repeatability and a 36x20-inch work area. The tool can handle throughput of 2600 units per hour. Like the EV Group product, the Palomar die bonder targets LED makers looking to boost manufacturing volumes.

GaN-on-Si industrial affiliation program

In the area of research, Imec is expanding its GaN-on-Si industrial affiliation program that it first launched last year. The program is focused on developing manufacturing equipment technologies for HB-LEDs using a silicon substrate. Micron Technology, Applied Material, and Ultratech have joined the program.

The transition to GaN-on-Si technology could allow LED manufacturing to transition from the relative-small 4-inch sapphire wafers used to day to 8-inch or larger silicon wafers. Generally in semiconductor manufacturing, larger wafers equate to increased manufacturing volumes and lower component prices.

Rudi Cartuyvels, Vice President & General Manager Process Technology at imec stated: “We are excited to welcome 3 major companies to our GaN-on-Si IIAP. Less than a year after the program’s launch in July 2009, we have assembled a strong consortium, including IDMs and equipment suppliers, and we expect more companies to join in the near future. This collaboration reflects the value of imec’s research on GaN-on-Si as a reliable cost-effective solution for next-generation LED and power electronics devices.”

The HB-LED news and sessions at Semicon West clearly indicate the growing importance and potential of LED technology. The conference has generally focused on highly-dense digital ICs, along with manufacturing techniques for precision analog ICs. LED manufacturing is quite different from either, but the market potential has players that have concentrated on the IC space looking to LEDs for new opportunities.

About the Author

Maury Wright is the Senior Technical Editor of LEDs Magazine.

This article was originally published here: LINK

Light+Building showcases sophisticated LEDs(MAGAZINE)

admin — Mon, 14 Jun 2010 08:31:00 GMT

Light+Building Showcase

With more than 180,000 visitors, no-one can deny the status of Light+Building, held this year in mid-April in Frankfurt, Germany, as one of the world’s pre-eminent tradeshows for the lighting industry. LEDs were everywhere, at least in the halls focused on lighting technology and applications. As we discussed in the Commentary piece in our last issue, exhibition booths lit with LED-based fixtures are no longer a novelty. Many lighting companies have now moved well beyond the discussion phase and are clearly committed to incorporating LED technology into their current and future generations of fixtures. In this show report, we present some of the products that caught the eye.

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This article was published in the May/June 2010 issue of LEDs Magazine. To read the full version of this article, please visit our magazine page, where you can download FREE electronic PDF versions of all issues of LEDs Magazine. You can also request a print copy of LEDs Magazine (available by paid subscription) and sign up for our free weekly email newsletter.

About the Author

Tim Whitaker is the Editor of LEDs Magazine

This article was originally published here: LINK