LTPS - Page 9

We all know that LG Display managed to beat Samsung and be the first company to actually produce and ship OLED TV panels. Today the Korea Times claims that Samsung decided to adopt LG's own WRGB architecture and the company will start producing such OLED TV panels towards the end of 2013.

Samsung and LG have taken different paths towards large sized OLED panels. Samsung is using an LTPS backplane and a direct-emission (or side by side) architecture which means that there are three sub pixels for each pixel (red, green and blue). Samsung's design does not use any color filters. LG's OLED panels use an Oxide-TFT backplane and white sub pixels with color filters (this is called WRGB because there are four subpixels: red, green, blue and one white, non filtered. Is is also referred to sometimes as WOLED-CF).

Universal Display's CFO, Sidney Rosenblatt, participated in an investor conference (the 15th Annual Needham Growth Conference, January 15). This was an interesting presentation. Sidney confirmed that Samsung's next AMOLED products will include the company's green PHOLED material (and probably the host too), which will make them more efficient (by 25%). The new products will be released in Q1 or Q2 2013. According to reports, this will be the Full-HD 4.99" 440PPI display prototype shown at CES.

Regarding Samsung's flexible display program, Sidney says that Samsung is still using LTPS. The production process is too hot for the plastic substrate (it will melt) and so the LTPS transistors are deposited on glass and the glass is later delaminated. The encapsulation technology is Vitex's multi-layer technology which is very slow (the panel has to enter the evaporation chamber 6 times). All this means that plastic displays will be more expensive than glass ones.

Correction: according to our trusted source, this report was wrong - Tianma did not develop such an AMOLED display...

According to reports, Tianma developed a 4.5" Full-HD AMOLED panel. In a recent trial production run the company managed to produce the panels (in addition to 3.2" AMOLED panels as well). Tianma may be possible to mass produce these panels in 2013 - with an aim to become one of the world's leading smartphone display makers.

The company has a pilot 4.5-Gen AMOLED fab in Shanghai (it was reported in 2010 that the pilot line's cost was $72 million and the Chinese government helped with $40 million in funding). The pilot fab is able to produce around 1,000 glass substrates in a month. Tianma's prototype panels shown at SID (in June) used a direct-emission architecture and an LTPS backplane. I assume the new panels use the same architecture.

Display Central posted an interesting article (update: it is no longer available, sadly) discussing Samsung's Gen-8 AMOLED fab plans. They say that the company is still on track with their original plan - to start with LTPS production and later on switch to Oxide-TFT (IGZO). Samsung seems to think that IGZO is not ready yet for OLED mass production.

The article quotes Barry Young from the OLED Association saying that Samsung has managed to scale up LTPS for their Gen-8 pilot line and have now ordered high-volume Gen-8 production tool from APS.

Applied Materials announced two new film deposition systems, used to make high definition televisions and high-resolution mobile device displays - both OLEDs and LCDs. First up is the AKT-PX-PECVD system (shown below) that can be used to deposit LTPS films on large glass substrates (sized from 1.6 m² to 5.7 m²).

The second system, the AKT-PiVoT PVD system is used to deposit metal oxide-based TFTs (IGZO in particular). Applied says that this new system is capable of overcoming "mura effects" that reduce the quality of the display. It also offers "breakthrough" stability which makes is suitable for OLED displays and TVs.

DisplaySearch says that the AMOLED market is expected to grow almost tenfold from 2012 (2.3 million square meters) to 2016 (22 million square meters). DisplaySearch are basing their forecast on planned investments, and they say that most of the capacity increase will be driven by OLED TV production.

While Samsung has been successful in improving yields for small OLED production (to an almost-LCD level) and thus enabling an only 30% premium over LCDs, producing large OLED panels is still very expensive - mainly due to low yields and high material costs.

Air Liquide says it has been selected to supply ultra-pure carrier and electronic specialty gases to three new fabs manufacturing advanced display technologies, such as OLEDs, LTPS, MEMS, and OLED backlighting (we assume they mean OLED lighting). The fabs are located in Singapore, Japan and Taiwan. All those fabs will produce small/medium displays for smart phones and tablets.

We know of new OLED fabs in all those locations: in Japan several companies (such as Lumiotec, Mitsubishi and Panasonic) are producing OLED lighting panels. Both CMI and AUO in Taiwan are gearing up toward AMOLED production, and in Singapore AFPD (a 4.5-Gen LTPS fab owned by AUO) is also upgrading the LTPS LCD fab to OLED production. Any of these fabs may have selected Air Liquide's product.

A few weeks ago we reported that BOE Display started construction of their 5.5-Gen AMOLED fab in Ordos (Inner Mongolia). It seems that this is indeed true as BOE Display now details the new fab in their company profile brochure:

According to the brochure, the fab will produce 54K substrates a month, and will produce both LCD and AMOLED panels on LTPS backplanes. According to earlier reports, the fab cost is estimated at $3.44 billion. BOE's plan is apparently to first start with LTPS LCD and only in 2014 start producing AMOLED panels as well.

Tianma was showing two AMOLED prototypes at SID: a 3.2" (320x480) and a 12.1" (1280x800). Those are direct-emission (side-by-side) panels built on an LTPS substrate, and they were looking rather good. These seem to be the same panels demonstrated in FPD china earlier this year.

The panels were produced at Tianma's pilot 4.5-Gen AMOLED fab in Shanghai. It was reported in 2010 that the pilot line's cost was $72 million (the Chinese government helped with $40 million in funding) and it is able to produce around 1,000 glass substrates in a month.

Corning's major announcement at SID was the new Willow glass product. This is an ultra-slim (50 um and 100 um) flexible glass that can support backplanes and color filters in both LCD and OLED panels. Willow glass can withstand temperatures up to 500 degrees Celsius, and can be used in roll-to-roll production processes.

Corning says that in the near future Willow glass can be used to produce rigid OLEDs panels in processes that need flexible glass (such as roll-to-roll), and in the long term it may also lead to actual flexible panels based on glass. Glass have several advantages over plastics, mainly that it's a better barrier and it can result in better displays in terms of resolution, backplane speeds, etc. However the major disadvantage is that it can be shattered, unlike plastic-based displays.