Originally Posted by Desk.
So if this is the case, and if adopting an LTPS backplane would eliminate these remaining issues, giving much greater fine voltage control, delivering much higher yields, then why doesn't LG simply do just that?
Is it just down to cost, or is there some proprietary issue around LTPS?
It's cost. The LTPS cost is one of the main reasons Samsung isn't investing in OLED TV production yet. LG's slow ramp in production was to due to getting the oxide TFT yields up to the required rates. Here's a discussion...
8 mask oxide TFT production processes were reduced to 4 mask production and lowered investment cost, which led to a more reasonable panel price.
The halved number of masks in the TFT production signifies that the number of processes can be reduced and increase the yield rate. It also means the amount of large scale investment essential to the TFT production can be reduced by 50%.
The rival display of LCD mostly uses 4 mask process of a-Si TFT. If the existing Gen8 line, with capacity of 200K, is changed to LTPS TFT or 8 mask oxide TFT process, the capacity is reduced to approx.. 90K and increases the TFT production cost by more than 200%. However, in 4 mask production, the LCD line can be altered to TFT exclusive line for OLED without any loss of capacity; this would place the TFT production cost on the same level as LCD. Of course, as the existing line can be used without additional factory construction will reduce the investment cost even further.
Therefore, if OLED is developed using 4 mask oxide TFT technology, theoretically the production cost falls to the level of LCD panel production price excluding BLU. As the large area OLED panel market is in early stages, the OLED evaporator and encapsulation equipment price is still high, but the equipment price will fall rapidly within 2-3 years and the investment cost is also expected to be reduced.
The display market research organizations are estimating the large OLED panel price to be at least $3,000, but according to the 2015 Annual Report by UBI Research, the LG Display’s 55 inch FHD OLED panel price is only expected to be around $900, and a 55 inch UHD OLED panel is to be around $1,400. UBI Research analyses that there is some difference from the actual sales price as LG Display’s M2 line production and yield rates are low, but if the full capacity of 26K is reached and the yield rises to above 80%, the current supply price can easily be met. Particularly if the large scale mass production system is established with the addition of M3 and M4 lines, it is predicted that OLED panel price will be reduced so that there will only be 1.1 times difference compared to LCD panel.