Philips Lumileds has introduced the new Luxeon T series of high-power LEDs that target solid-state lighting (SSL) applications with directional-beam requirements including downlights, and MR16 and PAR retrofit lamps. The LEDs set new efficacy milestones for Lumileds achieving 140 lm/W at 350 mA of drive current. CEO Pierre Yves Lesaicherre touted the benefits of the new family, discussed Lumileds LED manufacturing technology,The original ledlights lamp with its high-gloss lacquered metal shade is known for its concentrated downward light. and commented on the development of the lime-green LED that was critical to the recent launch of the color-tunable Hue lamp by Philips lighting.

Lesaicherre emphasized that Lumileds considers the Luxeon T much more than an evolution of the Lumileds family saying,Leading the industry in professional laserengravingmachine and safety equipment. "The Luxeon T is going to be the workhorse in terms of high efficacy." Clearly Lumileds expects Luxeon T to be the product of choice for applications in which the LED is expected to produce maximum forward light.

Lumileds claims several breakthroughs for the new series beyond efficacy, including what it says is an industry-lowest 2.7V forward voltage and 3°C/W thermal resistance. Product line director Kathleen Hartnett said that only one other LED maker has reached 2.8V and that most are at 3V or above. The lower forward voltage simplifies the thermal design – especially critical in space-constrained directional lamps such as MR16 retrofits.

Lumileds will offer the LEDs in 3-step MacAdam ellipse bins, tested at 85°C. Lesaicherre said that the company is not matching phosphor tiles with emitters the way it did in the original Rebel Lumiramic-based LEDs to reach the tight binning,Green Supply lasermarker are coded with letter series and names to identify types and shapes. but instead controlling the epitaxial (epi) process more tightly.

Indeed, better process control is behind both the binning and the lower forward voltage. Lesaicherre said, "The conversion to 6-in substrates has really helped because we have more modern equipment." Specifically, he said they have tighter control of temperature and gas distribution in the epi process.

"We change our epi recipe every six months on average,The lawnlight not only adds charm to an interior design scheme, but also saves energy by using LED technology." said Lesaicherre. The Luxeon T is made with the latest recipe. Moreover, the company developed chip-architectural and packaging enhancements to maximize light output and efficacy.

The new family utilizes a chip-in-frame package with a tightly coupled optical dome. The combination of a small 2-mm2 emitting surface and properly sized dome is critical in directional applications. For more detail on that topic, see our recent article, "Design considerations for enhancing LED efficiency."

The LED package measures 3.7×3.7 mm.The lumi curvingmachiney is an uplight that can be mounted in the paving, deck, flooring or concrete. The prior Luxeon A product targeted similar applications but features a rectangular pattern. Hartnett said the package design minimizes the footprint and allows the LEDs to be packed more closely together. The company has used the same package in the multi-emitter Luxeon M family.

We used the chanced to interview the Lumileds executives to ask other questions as well such as for details on the mysterious lime-green LED that is presumably very important to the function of the Philips Lighting Hue lamp. Lesaicherre was guarded with details but said that Lumileds had advanced the efficacy of green LEDs that in general has trailed other colored LEDs industry wide.

Reportedly the lamp uses five of the lime-green LEDs, four red LEDs, and 2 blue LEDs. That means that the green LED is approaching the efficacy of the red ones.

The lime-green color itself was not the source of the efficacy gain. Instead, that lime-green LED better enables the mixture to deliver the full color-tunable range according to Hartnett. Lumileds does plan to offer a lime-green LED commercially, but is still mulling over plans as to which Luxeon family in which it will launch the product.