Capacitive touch screen industry technology
Touch Panel (TP), also known as "touch screen" and "touch panel", is an information input device that realizes human-computer interaction by means of touch sensor technology. According to different working principles, touch screens can be divided into resistive, capacitive, optical, ultrasonic and electromagnetic induction. Among them, capacitive touch screen has the characteristics of high sensitivity, good light transmission, strong stability and long service life, and supports multi-touch. It is the current mainstream technology product and is widely used in smart consumer electronics, industrial control medical equipment, intelligent Home, office equipment, automotive electronics and other fields. From the perspective of different technical routes, capacitive touch screens can be divided into two types: external and embedded.
The basic structure of the external capacitive screen is that the touch panel is separated from the liquid crystal panel. There are mainly two solutions: film type and glass type. The difference between the two is that the carrier of the touch layer is different. The thin film scheme includes GFF (cover plate + ITO film + ITO film) and derived GF (cover plate + ITO film), etc. Compared with the GFF scheme, GF saves a layer of film. Glass solutions include GG (cover + ITO glass) and OGS (integrated touch). OGS is an upgraded solution of GG. Generally speaking, the advantages of the plug-in structure scheme are simple process, mature process and low cost.
The built-in capacitive screen integrates the touch panel and the liquid crystal panel, mainly including In-Cell and OnCell. Compared with the external structure, the embedded capacitive screen has the characteristics of thinness and high light transmission, but due to the high technical threshold, it needs to integrate the thin film transistor array circuit, which involves the development of photomask and process technology, which will increase the production cost. At present, the main application fields of embedded capacitive screens are mostly concentrated in the smartphone market.