There was a rumor that the iPad would adopt IGZO IGZO technology can greatly reduce the power consumption of Apple's screen, so that the iPad can not be equipped with such a large capacity battery, reducing the weight and thickness. Seeing that IGZO brings so many benefits, some people begin to imagine that the iPhone will also use IGZO. However, it is actually a technical setback if the iPhone also uses the iGZO screen.

The figure below shows several main TFT technologies, A-SI, iGZO and LTPS. Amorphous silicon refers to A-SI, and the current iPad uses A-SI technology.

From the figure, we can see that the electronic mobility of the screen is increasing from left to right. High mobility means that the use of transistors with smaller geometric dimensions can provide sufficient charging capacity and the capacitance value is higher than that of traditional amorphous silicon, thus improving the opening ratio of LCD panel pixels, so the effective area of light penetration becomes larger. Less backlight tubes or lower power consumption can be used to achieve the same brightness, so as to save energy and electricity.

Compared with its traditional A-SI, IGZO's electrocrystal volume is smaller, which can improve the opening ratio of LCD panel pixels, so as to save power for existing iPads. However, compared with LTPS, IGZO is still inferior. The idea migration of LTPS is faster, more than 10 times that of IGZO, and more than 100 times that of A-SI.

LTPS is obviously better than IGZO, but LTPS is not a new technology. It has been used on many high ppi mobile phones, such as Apple's iPhone 5 iPhone 4s/4、HTC One X、 Xiaomi 2 and others use LTPS technology.

Why was it said that the iPad used IGZO instead of LTPS before? This is mainly because the production process of LTPS is relatively complex. During the packaging process of LTPS, glass with A-SI structure needs to be scanned by laser. When amorphous silicon absorbs the energy of laser, it can become polycrystalline silicon. Its electron mobility is more than 100 times higher than that of amorphous silicon, which is conducive to the miniaturization of TFT components, improving the opening rate of the panel, improving the brightness of the display screen, and reducing power consumption.

IGZO's transformation of the production line is less difficult. Panel manufacturers can produce small and medium-sized panels only by slightly modifying the production line that originally produced large panels, which can bring more output and lower costs. Therefore, Apple decided to use IGZO technology on the iPad with large screen.