LG Display Co Ltd announced its roadmap for developing and releasing large-size OLED panels at FPD International 2009, which takes place from Oct 28 to 30, 2009, at Pacifico Yokohama, Yokohama City, Japan.

Won Kim, LG Display’s OLED sales and marketing VP, took the podium.

LG Electronics Inc plans to release a 15-inch OLED TV with a panel developed by LG Display at the end of 2009. The panel has a pixel count of 1,366 x 768 and a resolution of 105ppi. Its maximum screen luminance with an all-white signal and an all-black signal are 200cd/m2 and 0.01cd/m2, respectively. The peak luminance is 450cd/m2.

The panel is a bottom emission type and uses low-temperature polycrystal Si-TFTs that are crystallized by a high-temperature process (solid phase crystallization or SPC) as driver elements. Those specifications were announced at IMID 2009, a trade show that took place in October 2009 in Korea.

After the 15-inch panel, LG Display plans to release 20-inch and larger OLED panels in 2010, 30-inch and larger panels in 2011 and 40-inch and larger panels in 2012.

"Forty-inch and larger OLED panels will be fairly expensive in 2012, but they will be available in the market," Kim said.

’OLED panels will cost less than LCD panels in 2016’

In regard to technical challenges to stably supplying large-size OLED panels at low cost, Kim mentioned (1) driver elements (TFTs), (2) organic EL materials and film forming processes and (3) sealing processes.


Driver element

As for driver elements, LG Display will probably employ a TFT based on a low-temperature polycrystal silicon (and SPC method) or an oxide semiconductor such as IGZO (In-Ga-Zn-O), he said. However, he also said that TFTs based on those materials have some problems.

"We will be able to use a low-temperature polycrystal silicon with the sixth-generation size glass substrate," Kim said. "However, for 40-inch and larger panels, we have to use the eighth-generation size glass substrate. Therefore, we have to develop equipment that can deal with an SPC process at a temperature of more than 700°C."

As for oxide semiconductor, he said that it is one of the candidate materials to be used for large panels. But it has low reproducibility because of variation among lots, he said.

Organic EL material / Sealing process

LG Display plans to use fluorescent materials until 2011 and phosphorescent materials thereafter. Also, as film forming processes, the company is considering using printing technologies, starting from an evaporation method with a metal stencil mask.

"In regard to sealing process, we believe that solid sealing is desirable for TV panels," Kim said.

With those measures, LG Display aims to achieve a 50% higher material cost and a 30% lower yield than those of LCD panels in 2012 and a 20-30% lower material cost and an equivalent yield in 2016.

At the exhibition site, the company exhibited the 15-inch OLED display, which was unveiled at IMID 2009, for the first time in Japan.