A while ago I had placed some questions to Luminus Devices, the makers of the Phlatlight LED and other innovative lighting solutions using the light-emitting diode. My questions hit the hands of Don McDaniel, the Director of Technical Lighting Solutions at Luminus Devices – I have put the Q+A below. A big thanks to Bill Keeler for getting all the right hands involved. Thanks Bill! We’re looking forward to reviewing Luminus products at LDI this year in Orlando!
JimOnLight: Luminus has been getting a lot of press about the PhlatLight; recent news announcing the PhlatLight Color-Mixing CBM-380 chip has reached me in several formats. How does the PhlatLight multi-color LED wafer compare to the Luxeon products in close categories?
Don McDaniel: The PhlatLight CBM-380-RGBW and the SBM-160-RGBW announced during PLASA ’09 put out far more light than any other 4-chip color mixing package on the market. The product premise is that in order to make illumination products that can replace discharge products, you’ve got to deliver a lot of LED chip area. To collect and color mix that effectively, you’ve got to pack that die area together as tightly as possible. Every optic designer wishes to have a point source to design around. Filaments come pretty close; LEDs don’t. Luminus has developed products that deliver a really useful amount of light from a single package and do so from the smallest possible total emitting area. This has enabled color mixed performance in form factors never before seen in the industry.
The other approach to delivering a lot of color-tunable lumens is large multichip arrays. These are certainly able to deliver substantial light, and are suitable for many applications, but optical designs to efficiently collect and shape the output are very challenging due to the large total emitting area of such packages.
JimOnLight: One aspect of the PhlatLight chips that appears to be provocative and popular with companies employing PhlatLight products is the modularity of the design. Can you elaborate a little on the PhlatLight technology and how Luminus arrived there?
Don McDaniel: Luminus Devices has operated from the very beginning with a “Platform Approach” to product design. The idea being that by developing a range of chip and package platforms, we could then cost effectively mix and match them to create differentiated products that enable our customers in unique ways. Furthermore, we could do so with modest investment barriers so that we could profitably address interesting niches. Our PhlatLight LED portfolio speaks the language of our platform approach. We continue to explore new application opportunities and use customer feedback to generate and evaluate new product variants.
If the question refers to the fact that we have many bolt-on, replaceable products, the answer is different:
Luminus was founded in 2002 with the goal of replacing discharge lamps in rear projection DLP televisions. To do so, Luminus developed 100W LEDs! The thermal requirements fundamentally influenced our approach to epitaxial, process, and of course package design. The chip-on-board package of our highest output products reflects that learning and development, from the 0.7 C/W package thermal resistance to the custom high current connectors and finally, to the screw down package design. This package continues to be of value for customers wanting to design in the ability to upgrade or replace LED modules in the future.
JimOnLight: Given the collimated nature of the PhlatLight’s radiation patterns, does Luminus find activity in specific product design and manufacturing categories over others? Are certain fixture types more a natural fit for the light qualities provided by the PhlatLight?
Don McDaniel: The PhlatLight collimation offers improved optical collection efficiency, particularly in projection type optical systems. With the increasing importance of white LEDs even in color tunable entertainment applications, this is perhaps becoming somewhat less important. While Luminus has developed IP for fabrication of collimated white LEDs, current phosphor processes cause light scattering that largely negates PhlatLight collimation. However, the photonic lattice technology remains an important part of big-chip white LED design, as the enhanced extraction efficiency allows us to maintain efficacy which otherwise diminishes as chip area is scaled up.
JimOnLight: The Luminus website mentions Entertainment lighting as an avenue of exploration for the PhlatLight. Would you elaborate on which avenues the PhlatLight is experiencing popularity? Is PhlatLight being used in any high output wash or spot fixtures or other entertainment technology?
Don McDaniel: Philips Vari*Lite has been quite candid in disclosing that their revolutionary VLX moving head wash uses seven of our CBM-380-RGBW modules to deliver 15,000 lumens of white light and dramatic saturated and pastel hues. That product has received an enthusiastic reception from the market and we’re honored to be a part of it.
There are a number of entertainment products in various stages of evaluation, demonstration, prototype and production release. These include color washes, color spots, white spots and other smaller fixtures. You can expect to see several prototypes and production releases at LDI next month.
JimOnLight: Does Luminus have any ongoing product agreements or development relationships with Entertainment lighting manufacturers and designers? The entertainment lighting industry has been generating tons of news lately on LED development – where does Luminus play into that development?
Don McDaniel: While we have no exclusivity agreements or product development relationships with any customers or partners, we work closely with many of our customers on product development and design. We have the technical resources to provide our customers with a very deep level of applications support which we feel is extremely important given the revolutionary nature of many of our products.
JimOnLight: Tell me about Luminus’ high-bay illumination division – has the PhlatLight product used in high-bay lighting had any case studies or other successful venture stories that you could share?
Don McDaniel: We showcased a high bay prototype with Affineon Lighting of Florida in our booth at Light Fair this year that used three PhlatLight LED CSM-360-W modules. The display generated a great deal of interest for Affineon which is now developing a range of products around that part.
JimOnLight: A growing movement of lighting designers, engineers, and manufacturers are exploring lumen output over time as a priority over accepting lumen maintenance and degradation. How do PhlatLight sources depreciate over time? As lamp life grows, are PhlatLight chips capable of maintaining a high output rate over competitor sources?
Don McDaniel: PhlatLight LEDs were designed from scratch to be able to operate efficiently and reliably under more than standard operating conditions. Fundamentally, the lumen depreciation physics of PhlatLight LEDs chips is the same as that of any other LED products operating under the same conditions, since our chip design optimizes heat and current distribution and light output. Any differences from one vendor to another are mostly related to package integrity and thermal management. Luminus is an industry leader in those areas; again as a direct result of our experience serving the consumer electronics market with 100W LEDs for RP-TVs. So, yes, PhlatLight LEDs are capable of delivering operating lifetimes perfectly competitive with, and often in excess of, the leading quality vendors in the industry.
A huge thanks to Don McDaniel and Bill Keeler from Luminus Devices for their time and effort! Make sure to check out the offerings from Luminus at their website, Luminus Devices. You can see detailed information on every product in this interview on their website.