To kick off the first day of conference sessions at The LED Show (Las Vegas, NV), Cree, Bridgelux, and Nichia took the stage in the first session, touting vastly different messages. Cree focused on the system-level aspects of solid-state lighting (SSL) design. Jason Posselt, vice president of channel marketing, asked why LEDs aren’t everywhere and answered his question noting high costs. Nichia closed with what was largely a product pitch but scored with a zinger at the end that we will get to a bit later.
Richie Richards, manager of applications engineering at Cree, presented, "Quality SSL: What is it?" About quality he said, "When you see it you know it. In SSL it’s the same thing." He noted that LED quality alone doesn't matter in a fixture design. The entire system design must be optimized to yield a quality product.
Richards said concerns about poor quality products derailing the momentum of SSL was the factor that led Cree to create the TEMPO (Thermal Electrical Mechanical Photmetric Optical) testing program that is offered to luminaire makers.
Richard unveiled a number of interesting facts about TEMPO. He said Cree hadn't limited the testing program to luminaires based on Cree LEDs. And he said that Cree was willing to share their testing techniques to help move the industry forward.
He also discussed some examples of tests that Cree performs. For example, the company performs thermal imaging on the electrolytic capacitor in the driver of an SSL product under test, since that capacitor is known as a primary source of failure in SSL products. Cree then provides the luminaire designer with a projection of the lifetime of that capacitor based on its specs and the condition under which it is being operated.
Richards discussed other items such as chemical gas problems and electronics driver performance. We will go into those areas in more detail in a future article in LEDs Magazine on the conference.
Richards did say that even large lighting companies are using the TEMPO service despite having their own testing equipment. Presumably Cree's testing confirms the products' performance or perhaps finds something the manufacturer missed. Richards closed noting customer successes saying a South African lighting manufacturer won a contract to supply 50,000 LED downlights to Kentucky Fried Chicken restaurants after delivering a TEMPO report.
Richards said LED quality isn’t enough. Industry standards such as LM-80 aren’t enough. Manufacturers need to perform a comprehensive system evaluation.
Bridgelux and cost
Bridgelux's Posselt opened with a quip about the lack of LED lighting in the meeting room. He said "we" get together several times a year at conferences to discuss the benefits of LED lighting, yet LEDs aren’t ubiquitous and asked why. The answer is that costs remain high.
Posselt presented Bridgelux's arrays as one way to mitigate the cost issue. He used retail applications as an example. Generally, stores want high-quality lights to highlight merchandise. And as you move to the high end of the retail market the demand can be for very-high-quality lights.
For such high-end applications Bridgelux announced its Decor line of arrays that feature a color rendering index (CRI) of 97. The company also has similar arrays in 80- and 90-CRI versions. Posselt said a company can design one product and drop in the array that matches customer requirements. The lighting maker may sell a majority of the 80-CRI products but can supply the higher-end versions when needed.
Still, LED component cost remains an issue upon which everyone is focused – even though the LED or LEDs are rarely the most expensive portion of an SSL product these days. Posselt touted Bridgelux's work on gallium-nitride-on-silicon (GaN-on-Si) manufacturing as the ultimate path to lower cost. Indeed, we just ran a news items on the topic with Toshiba announcing plans to manufacture such LEDs this year using Bridgelux technology.
Silicon-based manufacturing, as opposed to the use of sapphire substrates, could reduce costs in a number of ways. The silicon wafers cost less and are more widely available. But it’s the automation of the back end of the LED manufacturing process that is the key. A move to silicon would take advantage of automation from the IC industry.
Posselt suggested that anyone that had visited both an LED fab and an IC-industry fab would know the difference. About an LED fab he said, "It almost looks like child's play in a garage versus high-volume semiconductor manufacturing." And he said every LED maker was working on silicon manufacturing whether they would admit it or not.
Abdul Aslami, regional sales manager with Nichia, closed the first session mainly touting the scale of the company and the breadth of its product line. He said Nichia is both the largest LED maker globally and the largest supplier of phosphor globally. According to Aslami, the company manufactures 2.2 billion LEDs per month.
The company is offering components binned to a 4-step MacAdam ellipse today. Aslami said the goal was to get to a 1-step bin for all LEDs that target general illumination.
But clearly Aslami took issue with Posselt's comments about silicon. And of course Cree manufactures LEDs based on silicon-carbide wafers rather than sapphire. Aslami said, "We are not investing money or time on LED GaN on silicon." He said Nichia had investigated that technology previously and concluded that GaN on sapphire was optimum for LEDs and lighting.