Projected capacitive touchscreen 

Since the iPhone’s explosion on the market in 2007, multi-touch projected capacitive technology has forever changed the way we interact with machines and people alike.

In a projected capacitive touchscreen, there are two perpendicular layers of conductive coatings that form vertical and horizontal patterned tracks behind a top layer made from cover glass or PET. When a finger is placed on the surface it changes the mutual capacitance between the horizontal and vertical patterned tracks. The controller scans each cell of the horizontal and vertical grid with a high frequency signal, identifying any changes in mutual capacitance between adjacent cells as touch locations.

In most cases, projected capacitive touch screen is made from three major parts: sensor (can be glass, can be film), cover lens(can be glass, PCB, PMMA, PET...), and flexible printed circuit with controller(FPC). The sensor is made up of a series of electrodes that are in vertical and horizontal direction, composed of a transparent conductive coating(ITO, silver, metal mesh etc), and are configured into rows and columns. Each electrode is routed back to a connected point where the FPC is bonded. The flexible printed circuit typically contains the IC(integrated circular) that is used for controlling the function of touch panel.