Thanks to their increasing light output, high-power LEDs are becoming an interesting option for medical products, industrial image processing, and UV hardening, to name just a few.
Hundreds of very densely packed power LED chips are needed to illuminate large-surface objects. This can lead to thermal problems.
On top of that, high demands are placed on unchanging optical parameters, especially in UV applications, such as wavelength, chromaticity, forward voltage, and light output. Fluctuating temperatures or very inhomogeneous temperature distribution across the power module are unacceptable. A joint project sponsored by VDI/VDE-IT Bavaria faced these challenges and developed compact LED modules with a high packing density and output.
The Electronic Applications Division at CeramTec GmbH supplied innovative aluminium nitride (AlN) liquid-cooled heat sinks. The Fraunhofer IZM institute in Oberpfaffenhofen designed the thermal and fluidic cooling. The Fraunhofer IZM institute in Berlin populated the ceramic heat sinks with LEDs using new bonding techniques, and Excelitas Technologies GmbH & Co KG (formerly PerkinElmer Elcos) in Pfaffenhofen produced the functional LED module with an optical compound and electrical and fluidic interfaces.
The compact CeramCool Box is made for homogeneous and efficient cooling of packing densities up to 100W/cm². Within a 16mm x 40mm x 40mm form factor, it provides a total cooling capacity of 1,600W at 90C. This translates into a temperature delta of 60K to the coolant.
The significant increase in output of the new cooling modules was made possible by several development projects. For example, the usual thermal bottleneck seen in glued components was avoided altogether through the development of new chip assembly techniques using optimized sintering processes for direct LED assembly on AlN ceramic heat sinks. The metalized Alunit ceramic creates efficient thermal coupling between the chip and the coolant.
Another area of emphasis was the development of a special thermal management system with even temperature distribution over the entire module that also takes other general conditions into account, such as scalability in every direction and simple handling. The CeramCool Box that resulted from this effort also allows quick adaptation of the illumination to the respective application requirements without any complex optics.
Fluid or liquid cooled lights would definitely have a future in crash test research where we need lots of light for high speed photogaphy, film or video. At a thousand frames a second lots of light is needed. Also for large screen projection systems, which may become common for room decoration and illumination, if the price continues to fall.
Also, how about using them for headlights? Spotlights for a maritime environment could certainly use a lower current source of light, and they could happily live with some kinds of cooling systems.
We use mercury vapor lamps for UV curing of our products and the heat output of the lamps is enough that we must use 5 Tons of HVAC to cool them while in the curing chamber for only 15 seconds or so. We would love to see UV LEDs that could cure without heating the product. This development may be a boon for UV Curing of products that cannot take the heat of present UV lamps. It is not the visible light that is most intriguing to us but the UV.
I don't think this technology really applies to simple home lighting or even high-intensity shop lighting. The light production efficiency is not any greater than more dispersed LED lighting with conventional cooling. The manufacturing methods described would be very expensive to manufacture in comparison to the light output. I could see this as a high-performance projector bulb, but as the article stated, the main focus is for industrial UV curing or other processes that require an incredibly intense light output.
The cooling block may be used for other heat dissipation purposes. High performance microchip cooling, laser components, etc.
As the development of this technology continues, I wonder if the water coolant will also be replaced by another type of coolant in order to achieve even further advancements.
I think this cooler could be used to keep computer processors cool too. Just bond it on top of the processor and then the 100-200W used should be no problem.
Interesting that good old ceramics once again save the day, in a cooling sort of way. Ceramics have been used for decades to help cool all kinds of chips in IC packages of various kinds. Every time they are supposedly on the way out, a new app comes along that needs what they have to offer.
@bdcst You have summed up my thoughts exactly! In addition to using the waste heat for air or water, what about a fiber-optic light distribution system? The intensity of 30 headlights would go a long way to providing the illumination needs of an entire house. When the house is completely vacant, there would only be one, central light source to turn off. And with that many lumens, it's conceivable that back-lit display devices could also pipe into the central source. Oh the possibilities... =]
Actually this might work for home lighting too. Use the intense beam for indirect lighting bounced from a ceiling or diffuser. Pipe the cooling loop through a home's heating system in winter to make use of the waste heat or in summer to help heat domestic hot water.
Wow. This is fantastic. We don't need the equivalent of 30 headlights for home lighting, but I don't think the integration of LED lighting into consumer products can happen soon enough. The use of Aluminum Nitride as the magic element bodes well in the face of reported global rare-earth shortages. Applications that do require this light intensity will need supplied liquid-coolant, but needs for cooling systems will be a great source of additional high-skills employment.
Using almost 200 light-emitting diodes in the front and back of the new 2014 CTS, Cadillac designers are showing how LEDs can change the character of a vehicle.
We looked at a number of sources to determine this year's greenest cars, from KBB to automotive trade magazines to environmental organizations. These 14 cars emerged as being great at either stretching fuel or reducing carbon footprint.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
1 
