16 MAY/JUNE 2017 LEDsmagazine.com
interview | SAPPHIRE ILLUMINEER
Wilm: Our customers are very interested in
the 10° binning. Some had already experienced
the problems described earlier, and the tighter
binning did not protect them from visible color
differences. Others don’t feel the urgency yet,
but still agree that the physiology is correct
and a color space based on a 10° observer may
be more reasonable. We are perfecting our
products with the 10° binning feature in the
COB [chip on board] LED, initially binning in
the 2° color space to enable our customers to
fulfill existing specifications and then performing an additional check in the 10° color
space to avoid large color variations. Therefore,
everyone who is using the Soleriq S13 with the
10° binning feature in their products is deploying a luminaire with a binning in the 10° color
space in the market. The target is, of course, to
go to a binning only in 10° to achieve the full
potential of color consistency also across LED
families, generations, and even manufacturers.
LEDs: Will Osram expand the program? Is it
still limited to the COB products at this point?
Wilm: Currently, the 10° binning feature is
limited to the COB products, but we are also
investigating extension to other product families. This will enable a complete mix bet ween
different LED packages and power classes
and ensure a solid color consistency. Our
work on new LEDs is also supported by extensive information and standardization efforts.
As you mentioned earlier, we need to promote
the idea in the lighting market, and an internationally recognized standard where independent color coordinates are defined would
help tremendously in this respect. We continue to work on these topics and will advise
of any developments.
LEDs: Can LED manufacturing evolve to
the point where binning may not be required?
Wilm: We would still need to inquire: What
are your requirements and what do you consider as binning? A quick light-up test of the
LED after the final assembly of chip and package may remain to ensure that the LED is
working properly. A measurement of characteristic parameters during this light-up test is
then also not a problem at all. From this measurement, we derive properties such as brightness, forward voltage, and color coordinates.
Now it is up to the requirements if, e.g., the
measured color coordinates match the expec-
tations. We are very confident that we could
target, produce, and hit with the color coordi-
nates inside an ANSI box, for example, and we
could in theory skip the color binning in this
case. If the requirement is a 1-SDCM ellipse,
the challenge is much higher and we don’t see
a way around color binning at this point. But
keep in mind that binning is also providing
additional information. Therefore, we don’t
think we will get rid of an LED measurement in
the future, and increasing the process capabil-
ities will increase the yield in the desired and
required properties such as color consistency.
To answer your question, with the increasing
demands on light quality and consistency, we
don’t see a “binning free” LED anytime soon.
LEDs: Switching gears, Osram also won a
Sapphire Award for the Duris P 10. Our judges
appreciated that the LED borrows some ele-
ments from the mid- and high-power sectors.
Do you see this as a trend going forward?
Wilm: Demands from customers will often
trigger new designs, and in this case the strong
demand for lower cost of the high-power LEDs
led to the combination of a cost-efficient lead
frame combined with high-luminance sur-face-emitter chips. In the past, these LEDs
have typically been realized with ceramic sub-mounts that have been reduced in size significantly to ensure a good cost position, but the
change to a copper lead frame is still one way
of offering a cost benefit with the Duris P 10 to
our customers. All our robustness and qualification tests have been very positive, and the
second-board reliability of this new approach
is especially outstanding. We can offer high
performance with excellent quality for an
attractive price, and the Duris P 10 is only one
LED out of the Duris P family. The smaller
members are the 2W Duris P8 and the 4W
Duris P9. With these products available, this
unique combination of elements of mid- and
high-power sectors is very promising, and we
definitely see this trend continuing.
LEDs: What about application areas
beyond general lighting? We know you have
worked in automotive. What are the latest
trends in that sector?
Wilm: If connected lighting is the trend in
general lighting, smart lighting is definitely
the upcoming development in automotive
lighting. Adaptive for ward lighting, where the
illumination of the road is adjusted based on
the respective traffic situation, is already avail-
able in many cars. However, the development
of the first smart pixelated LED headlamp,
also called µ AFS [micro-structured adaptive
front lighting system], is bringing this feature
to a completely new level [see http://bit.ly/2f
9pQNV for coverage of the initial prototype]. A
cross-industry research project has developed
a new generation of automotive illumination
systems by combining LED pixels and driver
circuitry. This system allows individual and
precise control of the 1024 pixels, ensuring
optimum light conditions at all times with-
out dazzling other drivers, leading to greater
safety and more convenient driving condi-
tions. This revolutionary combination is the
latest trend in the sector and may also inspire
other applications in different markets.
LEDs: You have also spoken at times
about horticultural lighting, right? Osram
is clearly among the leaders supplying components into that sector. But we are continually amazed at how fast things are changing.
Thoughts about light recipes evolve continuously. And now we are even hearing about
UV LEDs being added to the mix. Give us
some thoughts on horticulture.
Wilm: To be honest, when I heard the first
time about horticulture lighting I was smirking a bit. The idea of growing food under artificial lighting if sunlight is available for free
sounded, especially with pricey LED technology, more like a ridiculous notion than an
innovative idea. But maybe that also attracted
me to this application! Now, after several years
being involved in the horticulture lighting LED
business, I learned that horticulture lighting
is much more than just growing tomatoes.
The true benefit of LED technology is the easily adjustable light spectrum that enables you
to control the plant by changing the ratios,
intensity, and timing of the illumination and
influence its shape of growth, the time of flowering, and even the taste and nutritional content of the crop. The application has already
moved far away from supplemental lighting for
tomato greenhouses to complete plant factories or vertical farms featuring growth without daylight, to growth of medicinal plants
under sterile conditions where, for example,
one can harvest the foundation of cancer medicine from algae. There are so many things to
discover as we are now witnessing an exciting
time where a niche application for LEDs transforms into an innovative and paradigm-chang-ing illumination technology. In this world of an
aging society, mega cities, and tougher environmental and climate conditions, I see horticulture lighting as a small but important contribution to a better future.