The manufacturing cost of a 55" oxide TFT-based AMOLED
using white OLED with color filters is 8 times that of a
high-end 55" TFT LCD display of equal size, a research
says.
Active-matrix organic light-emitting diode (AMOLED)
represents a rapidly growing and highly promising
technology for all display applications. Based on planned
investments, NPD DisplaySearch forecasts that the market
will grow nearly tenfold from 2.3M square meters in 2012 to
more than 22M in 2016.
Most AMOLED capacity is currently dedicated to small/medium
production for smart phones, but much of the capacity
increase going forward is expected to be driven by fabs
dedicated to TV production. There are many unknowns about
how far and how fast it will develop, though, since AMOLED
technology has not yet been proven in large-size TVs.
According to the NPD DisplaySearch AMOLED Process Roadmap
Report, the manufacturing cost of a 55" oxide TFT-based
AMOLED using white OLED with color filters is 8 times that
of a high-end 55" TFT LCD display of equal size. The cost
multiplier of a 55" AMOLED module using red, green, and
blue OLED is 10 times. These higher costs are mainly a
result of low yields and high materials costs.
Jae-Hak Choi, Senior Analyst, FPD Manufacturing for NPD
DisplaySearch, noted, "While cost reduction in LCDs has
slowed, large panel AMOLED cost reduction is in its
infancy. In the long-term, new and improved processes,
printing technology, and higher performance materials will
reduce AMOLED costs to levels equal to or lower than
LCD."
Due to greater process maturity, the manufacturing cost
premium for a 4" AMOLED is less than 1.3 times that of a
similar-sized LCD. Samsung Display has been highly
successful in its small/medium AMOLED production because it
has been able to raise yields to near-LCD levels. This
implies that manufacturers can potentially lower large size
AMOLED TV costs to be competitive with LCD TVs in the
future.
In order to scale up to large sizes, advancements in
several aspects of AMOLED manufacturing are needed,
including the active matrix backplane, organic material
deposition, and encapsulation. Because oxide TFT requires
lower capital costs and is similar to existing amorphous
silicon TFT, it offers a strong alternative to the
low-temperature polysilicon (LTPS) TFT currently used for
AMOLED. However, there are many hurdles for mass production
of oxide TFT, particularly threshold voltage shifts, which
are continuing to prove problematic for AMOLED production.
While indium gallium zinc oxide (IGZO) and other forms of
oxide TFT show great promise for backplanes, progress in
scaling up LTPS production is also being made by increasing
the excimer laser beam width to 1300 mm. In addition, the
current method of depositing red, green, and blue materials
by evaporation through a fine metal mask is being
continuously improved. Pixel densities of 250 ppi are now
possible, and over 280 ppi is feasible.
"Despite these advancements, high resolution continues to
be a relative weakness for small/medium AMOLED compared to
LCDs. High resolution patterning such as laser induced
thermal imaging (LITI) and material improvements are still
required for AMOLED to be highly competitive for super high
resolution flat panel displays," Choi added.