Projected capacitive touch panels are widely used in mobile terminals. This paper introduced the principles and structures of common touch panels, focusing on the development of full In-cell technology. Full In-cell touch panels were realized by embedding touch IC into LCD IC, which can decrease the thickness of the module, and will become the mainstream. The 13.46 cm a-Si full In-cell touch panels were produced. Touch lines and data lines were set at the same layer. Organic layer and metal3 layer were omitted. Compared with the developed technology, two masks were saved at least. The costs reduces and the process is simplified. The touch frequency is 120 Hz. The key touch performances such as accuracy, precision, linearity and jitter can reach the industrial standards. The optical and reliability performances are comparable with the non In-cell pands.