Display resolution in smartphones is changing rapidly. In our Smartphone Quarterly report, we forecast that HD (720×1280) and FHD (1080×1920) resolution smartphones are growing the fastest this year. The key drivers are adoption of LTE, application processor development, and display cost reductions. However, driver ICs could be a limiting factor for high resolution displays.
Source: DisplaySearch Smartphone Quarterly
China Mobile, the biggest telecom operator in China, announced that their target for 4G mobile phone devices is 100M this year; most subsidies from China Mobile are for 4G only. China Mobile changed the LTE specification, and LTE models must now support 5 modes, including TD-LTE, TD-SCDMA, GSM, LTE FDD, and WCDMA. To meet this requirement, smartphones will need more components, requiring a larger PCB assembly. This means 4G smartphones will use displays of at least 4.5”. The larger area means that the battery can be larger while remaining thin. With such a large display, brands prefer to use HD for mid-range LTE smartphones, while FHD resolution will be increasing even faster. Low-end 4G smartphone resolution will be at least WVGA/FWVGA.
The main SoC chipset vendors to address the China LTE mobile phone market are Qualcomm and MediaTek. We expect MediaTek chipsets to be qualified by China telecom operators in Q2, which will push LTE smartphone development. Chipset makers are not only promoting premium LTE smartphones,they are also working with telecom operators to develop mid- and low-tier devices, including 64 bit chips with LTE for the mid-tier before Q3. The SoC designs from both makers support HD and FHD resolutions.
Falling display prices are another reason that HD and FHD smartphone demand is growing this year. Prices of 5” HD a-Si TFT LCD have fallen by 16% since the end of last year, and 5” FHD LTPS LCD prices fell by 13%. Panel makers are competing to gain share in China’s subsidized mobile device business.
The supply of driver ICs is a key indicator of HD and FHD display development for smartphones. To meet the requirements of mid- and low-end smartphones, most driver ICs for HD and FHD resolution do not include RAM, in order to increase outputs and reduce cost. Most HD and FHD driver ICs are manufactured in 8” semiconductor foundries, but these fabs also produce fingerprint sensors, CIS (CMOS image sensors), 4K TV driver ICs, touch controller ICs, and some analog ICs. If the demand from these other ICs is too high, it can reduce the output volume of mobile phone driver ICs, which despite having high volume, do not provide high profits compared to the other ICs.