BOE Develops 8K 120 Hz Panel
We saw news reports about a 500 Hz 27” gaming display developed by the Chinese panel maker BOE several weeks back. They also mentioned creating a 110-inch 120 Hz 8K panel but little more detail than that. As a result, we reached out to BOE to learn more about this activity.
First, the panel technology that has enabled the speedy 500 Hz response is the same as that of the 120 Hz panel. But this improved pixel driving speed must be distributed over the total pixels in the display. 500 Hz means the resolution of the panel is 1920×1080. By the time you get to 8K resolution, the fastest update rate is 120 Hz.
The backplane is fabricated using IGZO technology, sometimes called “Oxide”, one of the four leading technologies used to create the transistors on the display glass. The other three are amorphous-silicon (a-Si), Low-Temperature Poly-Silicon (LTPS) and Low-Temperature Poly-Silicon Oxide (LTPO). Amorphous-silicon-based displays are the backplane of choice in most LCDs, with LTPS, LTPO and IGZO occupying smaller but essential market segments.
For example, IGZO is used for white OLED TV backplanes, handheld devices, and higher performing 8K LCD TVs. Samsung Display’s new QD OLED displays are expected to use IGZO backplane technology and will be a significant driver for the growth of this technology.
According to a recent blog post by Ian Hendy, a Display Strategy Consultant at Hendy Consulting, “oxide transistors have fewer masks than LTPS (typically between 4 and 8 compared to 11+) and higher mobility than a-Si (meaning smaller, faster transistors, larger aperture ratios),”. “There are some additional benefits, such as capabilities to replicate some driving and multiplexing functionality in the borders of the display that reduce needed semiconductor ICs. Oxides also have low leakage current. However, there has not been quite enough performance to be a possible LTPS replacement or superior backplane for emissive technologies.” IGZO (and LTPO) also enables variable refresh rates – a critical new trend for power savings in mobile devices.
BOE is adopting IGZO for its 8K panels at 120 Hz. But establishing this capability requires the development of many processes and materials.
8K panels with 120 Hz response using IGZO backplane technology have been produced before. However, as you get to very large sizes, the ability to drive at these high frequencies becomes more difficult. That is because the resistance of the driver and data lines become higher as they get longer, lowering the operating frequency of the panel (R-C roll off).
BOE has solved this challenge by developing highly conductive copper-based interconnect technology. The use of copper can be tricky as it can diffuse and oxidize, but BOE has apparently solved these issues by covering the copper lines with a silicon nitride barrier.
The 110-inch 8K panel will main be aimed at commercial applications, not consumer homes. And it will be expensive. BOE confirmed that their IGZO technology has not yet been implemented on any 10.5G lines, which are best optimized for larger-sized panels.
Below is a picture of the display and the specifications we received from BOE. The company also offers a 75” 8K panel, presumably, with similar specifications.