The impact of the emergence of Chinese manufacturing was not overlooked this year during SID last month, with the opening keynote talk delivered by Wang Dongsheng, president and co-founder of BOE, the largest Chinese display manufacturer.
With over 20,000 usable patents and 4,200 patent applications, BOE is in growth mode on a massive scale, with 35% of its products globally launched in 2013. The company is obviously looking to make significant profits from the juggernaut that is the display industry, with an accumulated investment of $260 billion since 1990.
Wang Dongsheng though used the term during his keynote "The display industry is suffering from success", referring to its low profitability.
As a way forward, and discussing BOE's roadmap, Wang Dongsheng highlighted the need for disruptive innovation that will solve challenges and create added value to the consumer. Via the route of providing value to the consumer, BOE is aiming for increased customer satisfaction in order to increase profitability.
On the OLED display front, BOE is quickly catching up with leading Korean manufacturers, launching a 17'' AMOLED display in 2013 and a 30'' AMOLED in 2014. BOE also demonstrated a 55'' OLED prototype at SID, with a contrast ration of over 100,000:1 and a thickness of less than 5mm.
BOE is also by far the leader in AMOLED display manufacturing in China, as showcased by the following chart that shows the activity of different mainland China manufacturers in different display technologies.
Table 1: Activity of different mainland China manufacturers in different display technologies
Dr Michael Heckmeier with Merck discussed the activities of the €11 billion material supplier in the display sector. According to Dr Heckmeier, growth in LCDs is expected from UB FFS increasing resolutions while 3DTV will struggle: Consumers still hesitate with the adoption of 3D TV as long as its necessary to wear glasses in order to experience it, it's a "prop" that consumers are still unwilling to accept. Dr Heckmeier mentioned instead seereal's 3D holography technology, a no-glasses 3D display technology that he feels will have a lot of potential in the future.
As for OLED displays, Dr Heckmeier discussed the cross fertilization between LCDs and OLEDs, focusing on flexible OLED and the advances in that space: soon after curved OLEDs were demonstrated, curved LCD product concepts started being researched. Solution processable OLEDs are still a priority for Merck with a lot of the materials research and development work within the company focused towards this space.
Finally, since LCDs are looking to proliferate in other segments than the display market, Dr Heckmeier expressed interest in LC smart energy glass for increased energy efficiency and LCs for antenna modulation technology, such as the one developed by Kymeta.
Finally, SONY's Dr Kazumasa Nomoto discussed the company's efforts in increasing immersiveness with 4K displays (LCD, OLED and UST projectors) and even 8K later on.
As the development of flexible displays continues with increased interest, companies are starting to focus on optimizing manufacturing processes and reducing costs. An interesting example of this is the research work from AUO, who presented a paper on debonding polyimide from carrier glass. Polyimide is being utilized as the TFT deposition technology is still high temperature so cheaper substrates such as PET or PEN won't perform adequately.
At the same time, laser debonding techniques are inherently expensive, so AUO has focused on mechanical de-bonding. In order to achieve minimum effects on the flexible substrate during the debonding process, the company has been working on the development of a nanoparticle based de-bonding interlayer with hydrophobic modifications, in order to create a weakened interface between the polyimide and the carrier glass. Using PDMS-modified SiO2 leads to the reduction of the necessary force to debond the polyimide from the glass.
AUO also presented on their 4.3in AMOLED with U-LTPS TFTs keeping the process temperature under 400oC. AUO completed its focus on flexible display challenges by discussing the flexible barrier they used for the display that achieved a 10-6 gr/sq.m.day water vapor transmission rate.
Work also continues by many others on developing flexible barriers, with Lintec developing a 10-5 gr/sq.m.day barrier while Princeton University continues to work with UDC in their development of their barrier layer (still very secretively with very little information available on its characteristics) while companies like Uniglobe Kisco of Japan are developing new measurements techniques of water vapor and oxygen transmission rates, in an effort to reduce measurement times.
LG and Samsung of course had on display in their exhibition booths their flexible displays (even though they are still encapsulated in rigid glass), but Nokia discussed their tri-fold flexible OLED as well as a similar book-type OLED display that they have in development. The WTC (white tandem OLED, top emission and color filter) displays, are utilizing IGZO TFTs and were tested at 100,000 times folding at 2mm bending radius showing no signs of damage.
BOE also discussed its own efforts in developing a flexible OLEDs. A 9.55in a-IGZO device on a polyimide substrate was presented, that was debonded from its carrier glass via laser lift off. The complete thickness of the device was about 220microns, with barriers being 200microns thick (120micron top barrier, 80micron bottom barrier), while the actual active layers (OLEDs and TFTs) had a thickness of 20microns. The device was able to withstand 10,000 cycles of the rolling test, at a 20mm radius of curvature.
Most of the major developers are demonstrating microdisplays, preparing for integration in wearable technologies with KAIST discussing some interesting supporting work on PU and PVA planarization layers in order to deposit soft fabric-based OLEDs. But obviously, one of the most eagerly anticipated presentations came from Google's Mark Spitzer who discussed the challenges of bringing Google Glass to market, concluding that:
- Individual figures of merit (such as numbers of pixels, field of view, etc.) must be considered as part of a system requirement based on user needs and don't necessarily need to be instantly characterized by maximum possible metrics.
- Look and comfort will remain much more important than any technical figures of merit if adoption is going to be strong but also, most significantly,
- All technologies needed for eyewear based computers and displays appear to be in hand.
What is now the final and most important step is seamless integration into desirable products that will captivate consumers.
Learn more at the next leading event on the topic: Printed Electronics Europe 2020 on 13 - 14 May 2020 at Estrel Convention Center, Berlin, Germany hosted by IDTechEx.