LTPO is the abbreviation of low temperature polycrystalline oxide (LTPO = LTPS+ oxide), and two TFT devices LTPS and oxide are integrated in the same pixel. The oxide is the bottom gate structure and the LTPS is the top gate structure.
This new technology combines the advantages of strong driving ability of LTPS TFT process and low power consumption of Oxde TFT process, and is applied to Apple Watch Series 5 model by Apple. It is precisely because of this technology that Series 5 has a constant screen display and has the same battery life of 18 hours as Series 4.
According to the process patent document, LTPO needs to build an oxide layer on the basis of LTPS. Last year, one of the most important issues was that manufacturers needed to ensure that the transistor characteristics in the original LTPS interlayer dielectric would not be affected when the oxide layer was laid. As Apple began to mass-produce OLED screens with LTPO and put them on Apple Watch, which has the largest share of smart watches, it proved that Apple has taken a big step forward in mass production of LTPO.
As we all know, Apple's transition to organic light-emitting diodes began with Apple Watch in 20 15 years, and then extended to iPhone X in 20 17 years. Therefore, the LTPO process does not stop at the organic light-emitting diode screen of Apple Watch Series 5, but the ultimate goal is to use larger screens, such as iPhone, iPad and even MacBook. This process is not expected to last long.