Oxide TFT - Page 14

Last week we reported that AUO plans to unveil a new 4" flexible OLED prototype, and today we have a photo and some details of this new panel. It turns out that this bottom-emitting panel is only 0.3mm thick, and it offers a resolution of 240x320. It can be bent with a curvature radius of 10mm.

To create this display, AUO formed a resin substrate on a glass substrate and formed the driver elements and OLED elements on it. Then, the glass substrate and the resin substrate were separated. The driver is based on amorphous IGZO (InGaZnO) TFTs, formed in a vacuum process.

Corning launched a new glass called Lotus Glass, which was developed for cutting-edge displays - such as OLEDs and next-gen LCDs (based on LTPS and Oxide-TFTs). Corning explains that the new glass has a high annealing point that delivers the thermal and dimensional stability required by these new high-performance displays. Lotus Glass has already been qualified and is now in production.

Lotus Glass's intrinsic stability means it can withstand the manufacturing thermal cycles better than conventional glass, and so enable tighter design rules needed in advanced backplanes (which are needed for high resolution and fast response time). It's good to see a new glass substrate from Corning, although we're still waiting for Corning's future flexible glass as shown in their "Day made of glass" video released a few months ago (which features future designs made with durable, transparent and even flexible glass displays):

During AUO's conference call, the company gave some interesting updates on their OLED program. As was suggested before, the company is already sampling panels - these are 4" displays for smartphones that use RGB matrix and sport 247 PPI. AUO says that these displays will offer superior quality compared to Samsung's PenTile based displays, especially on fine text (of course samsung is also offering the RGB-matrix Super AMOLED Plus displays). The products will ship in Q2 2012, and the company is seeing interest from several device makers.

AUO's current capacity is 7000-8000 monthly substrates in their Gen-3.5 fab. In 2H 2012 the company plans to bring their Gen-4.5 fab online with a monthly capacity of 15,000 substrates.

AUO announced it will show several OLED prototypes at the FPD International 2011 exhibition later this week. The company will show a new 32" Full-HD OLED TV prototype. This TV uses a Metal Oxide TFT as backplane and is only 3mm thick. AUO says that the TV has a quick response time and high contrast ratio. Hopefully the company will unveil the specifications and commercialization plans during the conference.

AUO will also show a 4" Flexible AMOLED panel (which is based on Low Temperature Processed Metal Oxide TFT as backplane driver). This panel is only 0.3mm thick.

Update: according to new reports, the OLED-A was wrong and Samsung are still using a Shadow-Mask to fabricate Super AMOLED HD displays

The OLED Association published a very interesting paper discussing Samsung's and LG Display's efforts to scale OLED production to large size panels (specifically 55" OLED TVs). In the article, they say that Samsung will use an LTPS substrate with a SMS (Small Mask Scanning) method, while LGD plans to use an Oxide TFT and Kodak's White OLED with color filters architecture. We already reported about Samsung's SMS method a few weeks ago.

The article includes a very interesting comparison of the different deposition methods (FMM, LITI, SMS, Printing and LG's RGBW). They also claim that the new display in the Samsung Galaxy II LTE HD was produced using LITI.

Korea Investment & Securities produced an interesting investment report about the Korean and Taiwanese AMOLED industry. They focus on material and equipment suppliers. Basically they say that large OLED panels will be produced soon (by 2013 or 2014 at the latest) by both Samsung and LG, and they try to identify which companies will benefit from this OLED market expansion. They say that both LG and Samsung will eventually convert their lines to Oxide-TFTs.

Strangely they do not even mention Universal Display and Novaled - which are both major material suppliers to Samsung and LG - even though they do list a lot of "foreign" material suppliers such as Dow Chemical, Idemitsu Kosan, Merck and even Kodak (which is no longer into OLEDs...). In their analysis for Duksan, for example, they do not mention the fact that the green material is now supplied by Universal - which should reduce the company's revenue from OLEDs... So we do not vouch for this report...

We've got some interesting updates regarding Chimei Innolux (CMI) OLED program. As a reminder, CMI was born as a merger between Innolux, CMO and TPO. Both CMO (through its CMEL subsidiary) and TPO had active OLED programs, and CMEL were even producing panels up until the merger. CMI's own OLED plans are still unclear.

Back in February 2011 we reported that CMI indeed plans to start producing OLEDs in two plants - a Gen-3.5 (620x750mm) LTPS/OLED Plant in Jhunan, Taiwan and a Gen-5.5 (1,300x1,500) IGZO-TFT plant in Tainan (also in Taiwan). Later on there were reports that CMI actually scrapped all OLED plans for now. But in March the company unveiled a couple of new AMOLED prototypes (3.2" and 3.5", shown above).

Sony developed a new OLED panel that uses a self-aligned top-gate Oxide-TFT (IGZO). According to Sony, the image is improved over normal OLEDs as it reduces the unevenness in brightness (that is caused by parasitic capacitance between gate electrode and source/drain electrodes in the TFT). The new panel is 9.9" in size (960x540) and features 200cd/m² brightness, 1M:1 contrast ratio and 96% NTSC color gamut.

Sony's new TFT uses a self-aligned top-gate structure (Sony's older TFT used a bottom-gate structure). This makes it possible to keep a long enough distance between the gate electrode and the source/drain electrode - which reduces parasitic capacitance.

Update: We have some info and a new photo of Toshiba's flexible OLED prototype. See below.

Toshiba is showing an ultra thin (0.1mm) 3" flexible OLED panel prototype (160x120) that weights just one gram. The OLED is built using an oxide semiconductor TFT (IGZO) unto a plastic substrate. Toshiba says that they will be able to start producing displays based on this production method by 2014 or 2015.

Toshiba's OLED uses white OLED material with color filters. The architecture is bottom-emission. Toshiba says that the managed to lower the process temperature to 200°C, and so were able to use the plastic substrate.

Universal Display and the Flexible Display Center (FDC) at Arizona State University (ASU) have successfully fabricated full-color, flexible AMOLED display prototypes that use the FDC's bond/de-bond manufacturing process. The new display use UDC's PHOLED materials and the new single-layer encapsulation technology. The OLED are made on DuPont Teijin Films Teonex polyester film.

The displays made are 3.8" in size and offer QVGA (320x240) resolution. They produced several displays, some on LTPS and some on IGzO backplanes.