In the last year, the awareness and availability of mini and
micro LED technology has only grown. The biggest technology brands — LG, TCL,
and Samsung — launched new products at CES 2021 and others are rumoured to be
planning to launch their own products using mini LED technology this year.
Additionally, companies of all sizes are investing resources in bringing this
technology to consumers. Micro LED technology has a story of its own as the
even smaller die present challenges up and down the supply chain. Both
promising solid-state lighting (SSL) technologies face development roadblocks,
but innovation continues to address the challenges.
Brief history of micro and mini LEDs
LED technology was introduced in the mid-1960s. Generations
later, two researchers, Xongxing Jiang and Jingyu Lin, imagined small displays
and wearable displays illuminated with miniature LEDs. They envisioned
microscopic displays and projectors that would disrupt the technology of the
time and invented the first micro LEDs in 2000. Since then, major brands such
as Sony and Samsung have developed concept products that sparked interest in
the flexible, bright, and microscopic SSL technology. Although not yet mass
produced, video wall products using mini and micro LED technology are
commercially available. Samsung’s The Wall, Sony’s Crystal LED, and Konka’s
APHAEA Smart Wall are available to consumers, albeit at high price points.
When the development of mini LED placement technology began,
it was nearly impossible to source the unpackaged LEDs for experimentation. The
demand was so small that suppliers did not devote capacity or their own
development to the production of mini LEDs. Other issues arose in the adoption
of the technology involving precise substrates and the control of the mini LEDs
and optics on the final products. For some time, these roadblocks inhibited the
use of micro and mini LED technology in the development of future product
applications.
Today, however, most major LED manufacturers have mini LEDs
readily available. This is due in part to the promise that consumers and large
technology companies see in these microscopic light sources. The awareness of
the technology has grown significantly. At CES in January 2020, mini LED
technology was one of the most widely covered innovations of the entire trade
show, when four years ago, it was impossible to get a single die for
development.
Due to the increased demand for mini LED products, the
supply chain — from the wafers of die to the machines that place them — has
aligned around these new products. The rumours of the biggest names in
technology releasing their own mini-LED-based products has forced companies up
and down the supply chain to focus on mini and micro LED products and address
the issues to deliver end products to consumers.
Addressing mini LED supply chain problems .The first problem
the mini LED supply chain faced was acquiring the necessary LEDs. A single
product that uses mini LEDs can have hundreds of thousands of die compared to
hundreds of traditional LEDs in similar products.
In the last two years, suppliers have been forced to address
these significant supply chain issues due to rising demand from end consumers
and the promise of the technology. LED manufacturers have made significant
investments to build capacity for die production to ensure broad availability.
While the inside of a packaged LED is the same as what is
being used in an unpackaged LED such as the mini or micro format, more wafers
will be consumed because more devices will be required for the end product.
Therefore, the number of wafers processed will be much higher when there are
greater numbers of mini LEDs utilized in innovative new launches.
The substrate is the next roadblock requiring the industry’s
attention. Mini LEDs need a much higher level of precision for the substrate
than traditional LEDs. FPC and FR4 are the materials typically used today, but
the ideal substrate for mini LED applications is glass due to the ease of
placement, the surface flatness, and the low cost of production. All substrate
technology requires real quality improvement with a rigid and semigrid
substrate, but specific development is needed for circuitry, materials, and
placement methodologies to adopt the use of glass.
Some leading companies have started to experiment and even
develop products utilizing glass substrates. In the last year, there has been
visible progress in mini LED substrates, although more development is required.
The availability of glass substrates to product designers has allowed for wider
use of mini LED technology and paves the way for further adoption in the future.
For mini and micro LED applications, glass is used very
similarly to how it is used currently in other display technologies. Traces are
sputtered on just as they are for other technologies. Glass allows for much
more precise traces because it is an additive process rather than a subtractive
process. It enables active matrix displays. A gate can be made on top of the
glass to control the LED. In passive matrix displays, a driver can be
distributed on the glass using a similar technique to how the LED is distributed.
Proprietary placement processes are used to fix the mini and micro LEDs to the
traces.
Mini LED product development issues
After mini LEDs are successfully placed on the substrate,
controlling the light sources in the end product is the next development
challenge. A mini-LED-based product can have more than 100,000 die on a single
backplane. The question facing engineers is how to control those lights
effectively and efficiently. The chips that drive the LEDs and the distribution
of the control circuitry require additional technology advances to successfully
manage the lights at a reasonable cost.
The final obstacle facing mini LED products is the optics.
Dealing with thousands of light-emitting devices and the consumer’s sensitivity
to light proves to be a challenge. There are wide variations resulting from colours,
materials, and placement that the eye perceives. It is expected that many
vendors will focus efforts on creating a uniform backlight that looks amazing
to the human eye in the coming year. Different die locations, sizes, and types
will be used to solve the optics problem. Designers will be able to use these
variables to really optimize products for the consumer.
Proof of progress… and future implications
Despite a global pandemic and the impact on supply chains
across industries, technology development for mini LEDs was not deterred in
2020. Last year saw mass production for keyboard applications by Luumii, and
display products released from TCL, Konka, and Xiaomi available in certain
markets. In the first weeks of 2021, notable companies released their own
products thanks to the progress made in 2020. As more companies join LG,
Samsung, and TCL to release their own mini- or micro-LED-based products, the
supply chain will respond even more rapidly to make all components readily and
cost-effectively available. The manufacturing capacity will increase, allowing the
true mass production of products ranging from consumer electronics to large
video walls to mobility applications. The issues up and down the supply chain
will continue be addressed as consumers increase their demand for the newest
technology in their displays.
Micro LED technology, the smaller counterpart to the mini
LED, is a part of the conversation about the advancement of SSL technologies.
While most consumers would like to bypass mini LED technology and move to
compelling micro-LED-based products, substantial development will still be
needed to get these devices ready for the mass market. All of the innovation
issues that mini LED technology has faced will have to be overcome again with
micro LEDs. Due to the size of the much smaller die, the technical problems are
more fundamental. Growing micro LEDs and producing them effectively,
transporting and orienting them, and having the substrates optimized for them
are all problems currently lacking high-volume, commercially-available
solutions.
Every single step of the micro LED development process has
yet to be perfected for small batch production and even further for volume
production. It will be years before we see substantial developments for micro
LEDs, even as mini LEDs takes the stage this year with consumer product
launches.
Conclusion
As with any disruptive technology, mini and micro LED
technology has faced an uphill battle for there to be enough adoption to
encourage investment into mass production. This year, the market will continue
to see more mini-LED-based consumer products introduced as the largest
companies in the world see the value proposition of the technology and work to
solve the issues facing the supply chain. In the years to come, the world will
be watching as manufacturing and assembly progresses to enable the use of true
micro LEDs.
Li-Fi is a nascent technology that transmits data in much the same way as Wi-Fi, except that it uses lightwaves rather than radio frequencies as its medium. Proponents say it will help usher in the fledgling Internet of Things (IoT) because it will open up desperately needed bandwidth. They point out that the visible light spectrum is 10,000 times larger than the constrained radio spectrum.
The technology also potentially doubles the functionality of the ubiquitous lighting infrastructure by using it as an information pathway in which LED lamps and luminaires serve both as light sources and as communication transponders.
Li-Fi supporters also say that compared to Wi-Fi, it is less susceptible to interference and less likely to cause interference. On the other hand, Wi-Fi signals travel farther.
As a form of visible light communication (VLC), Li-Fi can have line-of-sight limitations. Nevertheless, Li-Fi could potentially serve many purposes, ranging from ordinary cafe web browsing to device-to-device communication.
The Fraunhofer Institute of Telecommunications, Heinrich Hertz Institute (HHI), will demonstrate a heavy-duty application at the Hannover Fair, a massive annual industrial and manufacturing exhibition where every year robots chuck around everything from cars to Chiclets.
In Fraunhofer’s Li-Fi demonstration, an inspection robot will transmit photographs over a Li- Fi system, Fraunhofer HHI project manager Dominic Schulz told LEDs Magazine.
It will be a proof-of-concept display of a system that when complete will send manufacturing instructions from factory ceiling lights to factory floor robots and thus support flexible, build- to-order car manufacturing processes.
Fraunhofer has been co-developing the technology, which it also calls “optical wireless communication,” with German lighting company Osram, German carmaker BMW, and Hungarian industrial automation firm Evopro.
“Using light as communication medium is a fascinating solution because there is little interference with existing technologies,” said Schulz. “We are convinced that we can efficiently use Li-Fi to meet many wireless communication requirements in business environments.”
The project, called “Optical Wireless Networks for Flexible Car Manufacturing Cells,” is part of a broader development initiative funded by the German Federal Ministry of Education and Research aimed at advancing wireless communications in industry.
Fraunhofer said the goal is “the creation of robust communication links even in cases of line- of-sight interruption.”
Its combination of lighting with industrial and IT technology is illustrative of how the
lighting industry is teaming with — and in some cases competing against — IT vendors such as Cisco, Google, Apple, and many more to turn LED lighting into an intelligent infrastructure that helps collect, route, and analyze data.
Cisco and Philips, for instance, have teamed to equip buildings in Holland and in Dubai with Power over Ethernet (PoE) lighting. Philips is also conducting trials of lighting-based indoor positioning systems in supermarkets including one in Dubai to help engage physical-world shoppers with offers. In the US, retail giant Target is also experimenting with similar technology from a different vendor.
Survey from North American lighting leader Osram Sylvania found
65 percent of Americans surveyed have purchased LEDs for use in their homes and
the majority (64 percent) of those who did, purchased LED bulbs for use in
sockets for general illumination. Of the respondents who were identified as LED
bulb users, the most valued benefits of making the switch were reduced energy
consumption (96%), longer bulb lifespan (93%) and cost savings (93%).
This industry-benchmark survey, which is a nationwide measure of public
attitudes about energy-efficient lighting and awareness of lighting trends,
also showed 78 percent of Americans switched to a more energy-efficient
lighting technology since the phase-out of incandescent light bulbs went into
effect in January 2014, with 30 percent of respondents indicating they made the
switch to LED bulbs. The two biggest drivers for LED light bulb purchases were
the lifespan of the bulb and the amount of light produced, with 95 percent of
respondents indicating these qualities had some influence on their decision.
“The increasingly rapid pace of innovation makes this an exciting time to be in
the lighting industry. As technology continues to advance, our objective has
been to give consumers the highest-quality products to fit their needs in this
new lighting landscape,” said Jes Munk Hansen, CEO Osram Americas and CEO Osram
Lamps. “We are committed to continuing that innovation and leading the industry
in a time of transition from analog to digital, from mechanical to smart and
connected.”
With the continued growth of the home automation and smart home markets, the
seventh edition of the Osram Sylvania Socket Survey also took a deeper look at
consumer attitudes and awareness of smart lighting technologies. While 62
percent of respondents indicated they were aware of smart lighting technology,
only 10 percent have actually purchased smart LED bulbs for their homes.
However, 83 percent of those surveyed believe smart lighting is a good
introduction to home automation technologies, and 72 percent felt smart
lighting will eventually replace traditional light bulbs.
Additional findings of the 2015 Osram Sylvania Socket Survey include:
Consumer habits and trends
• The top sources of information on lighting for consumers are in-store
displays and store employees (43%), product packaging (36%) and friends and
family (30%).
• Consumers who already use LED bulbs in the home are more likely to purchase
LED bulbs again (44%) as opposed to non-LED bulb users (18%).
• Millennials were more likely to switch to LED bulbs following the
incandescent phase out (38%) as opposed to those over 55 (22%).
New technology awareness and adoption
• Most respondents (86%) believe at least one room in their home would benefit
from smart lighting technology with living rooms (58%), kitchens (49%) and
bedrooms (42%) topping the list. However, the next most common hotspots were
not inside the home, but in outdoor applications (40%) and in the garage (36%).
• While price was not the top consideration for regular light bulb purchases,
it was the top purchase influence for smart lighting products (90%), followed
by the life span of the bulb (87%) and the ability to turn the bulbs on and off
remotely (74%).
• Though in the minority, current smart lighting owners are more likely to
expand their “smart” homes with other technologies than non-users with products
like smart thermostats (84% vs. 58%), house alarms (80% vs. 51%) and door locks
(80% vs. 45%).