How TV Manufacturers Can Get to an OLED Future

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Recent trends on display at both the IFA 2016 electronics show in Berlin, IBC 2016 in Amsterdam,  and CEDIA Expo 2016 in Dallas showed that large-screen televisions based on organic light emitting diode (OLED) technology are in for significant revenue and unit growth as multiple vendors  enter the market. Meanwhile, new OLED production technologies are gearing up to present more affordable alternative supply sources for large OLED screens needed to compete with models available today using LG Display sourced-WRGB OLED panels.

At the recent CEDIA Expo, LG announced the release of its newest 77-inch G6 Signature Series OLED TV for the U.S. market, just after a handful of manufacturers not named LG introduced at IFA OLED TVs using LG panels under their own trademarks focr Europe and Asia. (Read Stewart Wolpin’s recent report).

Despite the activity, OLED’s share of the overall TV market is likely to remain small for a few years, primarily because OLED panel production challenges continue to keep prices high and finished goods relegated to the ultra-premium segment of the consumer television market. OLED technology produces light emitting display panels, made by placing a series of organic (carbon based) thin films between two conductors. When fed electrical current light is produced. This self-emissive nature, which differs from LCD displays that require a separate back light, provides a number of advantages including the ability to shut off light at the pixel level to create deep black levels and high contrast ratios, ultra-thin panel depths and wide viewing angles.

LG’s current WRGB OLED panel production techniques that include the use of vapor deposition have relatively low yield rates (though improving every year) that produce a lot of wasted material compared to LCDs. These panels are also extremely sensitive to moisture and oxygen, requiring the use of a high-performance encapsulating layer. WRGB OLED technology produces a white light, with red, green and blue subpixels generated through the use of colored filters. This process is complex and can limit some panel brightness. Still, the process is more commercially viable in large screen sizes than other techniques produced to date.

In the past two years, LG Display has started selling its OLED panels to other TV manufacturers to broaden the market, while increasing competition for LG’s own consumer electronics businesses, but as long as the panels come from the same source using the same display technology, differentiation in performance and price is limited. Rivals to LG Display have been working feverishly on alternative approaches, some of which call for the use of a form of inkjet printing to efficiently apply the organic compounds that make up pixels onto large glass or plastic substrates. Nozzles can be used to spray these substances onto a substrate surface in ordinary atmospheric conditions. It’s expected this approach will increase yields and lower prices, while ramping up output to levels that could eventually rival LCD TV volumes, inkjet proponents have said.

Among the challenges is the fact that each pixel varies in size and number depending on the size and resolution level of each panel. The process of creating these pixels is highly sensitive and complex, requiring multiple layers of material to be deposited in exactly the right amounts for millions of individual pixels and subpixels, and must be properly dried to produce films that are perfectly flat. In addition, the soluble OLED materials needed for the inkjet printing process have been less effective than evaporable ones used in current vacuum thermal processes.

Promising solutions have recently emerged from a handful of companies including Kateeva, based in Newark, CA, which started in 2009 as an MIT-lab spinoff using more than $200 million in venture capital. It is generally believed to be the closest to delivering an inkjet-printing process for mass production of large screen OLED TVs. Investors include Samsung, Spark Capital, and TCL Capital, the venture capital arm of China’s TCL consumer electronics manufacturing company.

In November 2013, Kateeva unveiled its YIELDjet OLED inkjet printing system for high-volume OLED manufacturing. The process is said to include a pure nitrogen process chamber, which doubles pixel lifetime in certain applications, reduces particles up to 10 times using a specialized mechanical design and delivers film coating uniformity with a process window that’s five times wider than standard technologies. Kateeva is working in association with DuPont and Sumitomo Chemical to develop OLED inks suitable for printing directly onto a substrate. The challenge here is that deposited compounds must not exceed 50 nanometers and must be able to dry completely within 90 seconds. Instead of using filters to create colors, like LG’s WRGB panels, Kateeva said its process prints individual red, green, and blue subpixels, simplifying the manufacturing process. Kateeva reportedly expects to begin selling OLED inkjet printing equipment next year with panel production estimated to start as early as 2018. The company’s goal is reported to deliver OLED TVs with prices that can start at the $1,000 level.

Meanwhile, Tokyo Electron, a semiconductor equipment maker, is also developing OLED-printing tools in association with Seiko Epson, which has substantial patents in inkjet printing technologies through its consumer and commercial inkjet printing businesses. Tokyo Electron first began taking orders for its Elius 250 OLED inkjet printing system in 2014, but no announcements have been made about its use for large-screen TV applications as yet. Also in 2014, AU Optronics said it developed an OLED inkjet printing technology in collaboration with Merck, which is developing soluble OLED ink. The AUO OLED inkjet printer was capable of producing a 14-inch OLED panel. Merck is working closely with AUO to supply them with soluble OLED materials. AUO is still not mass producing commercial AMOLED panels, but the company seems to be close to doing so.

Merck also has been working with LG Display in supplying evaporable OLED materials and is working with LG to develop OLED inkjet printing materials as well. Also dabbling in OLED inkjet panel production is Konica Minolta, which said in 2012 it had developed a high-accuracy inkjet head capable of 1-picoliter drop size for printed electronics applications. The process is based on the company’s MEMS technologies. The print head is compatible with a wide range of ink viscosity levels and suitable for a range of printing applications, including OLED display patterning. In 2014, Sony and Panasonic combined their technologies for inkjet-based OLED through a JOLED venture. JOLED, which was being studied for acquisition by Japan Display, was planning to use a Gen-4.5 fab producing mid-size OLED panels, with production slated to begin by 2018.

There is no better display than OLED for showing off UHD content which is just now beginning to make a market appearance. If the industry can successfully invent more efficient manufacturing processes (along with lower retail prices), the combination of the two could kick start some high-end TV sales.

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